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At a maternal and child clinic at La Fossette, one of the largest in Cap-Haitian, patients arrive for regular check-ups as well as vaccinations. Four health workers work at the site, either vaccinating or weighing children. The clinic is held in a building in the process of being built.
Photo Credit: Karen Kasmauski/MCSP and Jhpiego
Rotary International advocacy visit to Ethiopia to support the polio eradication efforts and participate in the National Polio Immunization campaign in November 2014, where nationally, over 13 million children under the age of five will be vaccinated against polio. ©UNICEF Ethiopia/2014/Tsegaye
Area: Chandmari Juggi, Vijaynagar District: Ghaziabad, State: Uttar Pradesh Country: India, 22nd March 2017 .
An ANM (Auxiliary Nurse Midwife) administers polio drops and vaccination to pregnant women and children at an Angnawadi in the Chandmari Juggi. 27-year-old Naazma Begum along with her husband Mohhammed Avrakh reside in a 100 sq.feet plot of land covered by blue and yellow plastic supported by bamboo sticks. In order to survive Naazma picks rags from garbage dumps and construction sites, sometimes travelling around 8 to 10 kilometers a day. Typically her day starts at 4:00 am, and sometimes can extend till late evenings. After picking useful items out of garbage she comes back to her slum colony and sorts out the various pieces of junk collected. Plastic, metals, glass and other items are separated and sold. Children, young and old participate in this activity. The sorted items would then be sold to a “Kabadi Wala” ( Wholesale Junk Shop).
On certain days Naazma does not go for her morning rounds of rag picking. This does affects her household economically. Her husband a magician doing shows for a living does not have a steady stream of income. In spite of the circumstances Naazma on these mornings goes house to house motivating young mothers from her community to take their children for routine immunization sessions organized in her locality by the National Health Mission.
An inspiration to many, Naazma sometimes has tough time convincing her friends to take their children. Excuses ranging from, “We don’t have time’, “the child will get fever “ are common in her community. Naazma patiently explains the dangers caused due to lack of vaccination and its necessity in today’s life to every household. Her effort along with the support of Community Mobilization Coordinator and Block Mobilization Coordinator has led to a massive increase in the children immunized in Vijaynagar Ghaziabad.
Village Narayanpur, Samho Block, Dist. Begusarai, Bihar, INDIA. Vijay Ranjan, block mobilisation coordinater, explains Diarrhea prevention to a woman in Anganwadi centre at Narayanpur village in Begusarai, Bihar. Social Mobilisation Network (SMNet), a UNICEF-supported initiative which mobilizes the community at every level village, block, district, region, state to get their children immunized from basic diseases as part of the governments routine immunization programmes. SMNet was started essentially in the 2000s as part of the government's anti-Polio campaigns. SMNet officers thus operate at every level, starting from the village level (where there's a Community Mobilisation Coordinator, typically belonging to the village), to the block, district, sub-region, and region, where there are corresponding mobilizing coordinators for every block, district, sub-region etc. SMNet is premised on the idea that people from within the community are the best ones to mobilize others in their people be it their village, their block or district. But this is where officers such as Bijay Ranjan prove that familiarity is merely an added advantage to the mobilizing process: the real trick lies in effective communication. It is this that made SMNet successful to the extent that SMNET Bihar officers have gone on mobilization drives to other states such as Rajasthan, Madhya Pradesh etc. Although SMNet started as a tool to fight Polio campaign, over the years it has transcended its original definition, and become a pool of human resource that can be realigned to any other social/developmental goal. In fact, as of 2015, exactly a year after the WHO declared India as Polio Free, the SMNet is busy tackling diarrhea, malnutrition, hygiene and breast-feeding, all of which are critical to keeping Polio at bay. Immunization in India continues to be an ongoing challenge.
UNICEF India/2015/Dhiraj Singh.
UNICEF supports a nationwide measles vaccination campaign to protect 15.5 million children from life-threatening diseases. The launch of regional vaccination campaign in Haik town, Amhara region, Ethiopia 27 December 2022. In addition, integrating in the campaign, a range of other lifesaving services. These include COVID-19 jabs and catch-up immunizations for under-vaccinated children, screening for acute malnutrition, vitamin A drops and deworming against intestinal parasites. ©UNICEF Ethiopia/2022/Mulugeta Ayene
Josiane Pierre, a health worker, helps Rosemeline with her newborn, along with her mother, husband and two other children.
Photo Credit: Karen Kasmauski/MCSP and Jhpiego
Officials of Lagos State Ministry of Health immunize a child against Polio on Sunday, 1 April, 2012.
Polio is 99% near eradication with Nigeria , Afghanistan, and Pakistan topping about 20 countries still recording polio cases.
111 million children across 20 countries are targeted in current immunization campaigns worldwide.
Official Launch of the Polio Sub-NID, at the India Islamic Center in Lucknow, Uttar Pradesh, with Mullana Khalid Rasheed and District Magistrate A.K. Ghosh and visiting british rotarians , on November 8, 2009 . (photo Jean-Marc Giboux)
Seventeen shots in the first six months of a baby's life?! And they wonder why so many people have a fear of needles!
At a maternal and child clinic at La Fossette, one of the largest in Cap-Haitian, patients arrive for regular check-ups as well as vaccinations. Four health workers work at the site, either vaccinating or weighing children. The clinic is held in a building in the process of being built.
Photo Credit: Karen Kasmauski/MCSP and Jhpiego
Rotary International advocacy visit to Ethiopia to support the polio eradication efforts and participate in the National Polio Immunization campaign in November 2014, where nationally, over 13 million children under the age of five will be vaccinated against polio. ©UNICEF Ethiopia/2014/Tsegaye
Photo Credit: Allan Gichigi/MCSP
Pupils receive oral vitamin A immunization at their school in Bungoma County, Kenya 2016
At a maternal and child clinic at La Fossette, one of the largest in Cap-Haitian, patients arrive for regular check-ups as well as vaccinations.
Photo Credit: Karen Kasmauski/MCSP and Jhpiego
Kari Bergstrom, Manager, Immunization, Business with Alberta Health provides logistical highlights of the Provincial Vaccine Depot to Minister of Health Tyler Shandro and Deputy Minister of Health Paul Wynnyk on Monday, December 14, 2020.
Alberta will soon receive 25,350 doses of Pfizer vaccine and will start immunizing priority health-care workers provincewide.
During the week of Dec. 21, Alberta will receive shipments of vaccines from Pfizer at dedicated vaccine sites across the province.
Right now, the Pfizer vaccine must be administered at its delivery site, so these doses will be provided to respiratory therapists, intensive care unit physicians and staff, and eligible long-term care and designated supportive living workers across the province.
These are in addition to the 3,900 doses that are expected to arrive this week and will begin to be administered in Calgary and Edmonton within days of delivery. The ultra-cold freezers needed for the Pfizer vaccines are now installed at eight locations across Alberta and AHS staff are being trained to ensure quality and safety are maintained.
“This welcome news brings much-needed hope to Albertans, particularly health care workers, during this incredibly trying time in the pandemic. These staff are exhausted, and I hope seeing more vaccinations are on the way will show them there’s an end in sight. Albertans can be confident this vaccine is safe and will be administered quickly and efficiently.” said Minister Shandro.
“Alberta Health Services, Alberta Health and the COVID-19 task force have been hard at work preparing for the vaccine doses arriving this week and next. We have the plans in place to get the vaccines to where they need to go: into the arms of Albertans.” said Paul Wynnyk, chair, COVID-19 Vaccine Task Force.
“I am very pleased to hear that we will be able to immunize more of our front-line health-care workers and vulnerable Albertans before the end of the year. But this is not the end. We must continue to follow health measures to bend the curve, and until enough of us are immunized, we must continue to be each others’ vaccine.” said Dr. Deena Hinshaw, chief medical officer of health.
Pending final approval from Health Canada, the Moderna COVID-19 vaccine is expected to arrive in Alberta later in December. The Moderna vaccines can be transported to other locations, so the initial shipment will be used to immunize residents at long-term care locations beginning with those at highest risk, including two First Nations seniors facilities.
As more shipments arrive in early January, immunization will focus on Phase 1 priority populations and will include residents of long-term care and designated supportive living facilities, followed by seniors aged 75 and over and First Nations on reserve, Inuit and on-settlement Metis individuals aged 65 and over.
Phase 2 is still expected to start by April 2021 and will be targeted to the next groups of prioritized populations. Final decisions regarding eligibility in Phase 2 have not yet been determined.
Phase 3 will involve rolling out vaccinations to the general Alberta population, and is anticipated to start later in 2021.
(photography by Chris Schwarz/Government of Alberta)
A health worker giving a measles vaccine to a child in Amhara Region south Wollo zone at Hike IDP center. The launch of regional vaccination campaign in Amhara Region of Ethiopia 27 December 2022. In addition, integrating in the campaign, a range of other lifesaving services. These include COVID-19 jabs and catch-up immunizations for under-vaccinated children, screening for acute malnutrition, vitamin A drops and deworming against intestinal parasites. ©UNICEF Ethiopia/2022/Mulugeta Ayene
Official Launch of the Polio Sub-NID, at the India Islamic Center in Lucknow, Uttar Pradesh, with Mullana Khalid Rasheed and District Magistrate A.K. Ghosh and visiting british rotarians , on November 8, 2009 . (photo Jean-Marc Giboux)
Baby Elizabeth Ikabo in the arms of her mother Adanech Andebo, during the October 2010 measles and polio vaccination campaign - getting their vaccination registration cards. Moto village, Dale District, SNNPR, Ethiopia
©UNICEF Ethiopia/2010/Getachew
Adanech Andebo, carrying her Baby – Elizabeth Ikabo with her son Isaac Ikabo (blue top) and neighbours child Yohannes Lemma (red top) during the October 2010 mealses and polio vaccination campaign. Moto Village, Dale District, SNNPR. Isaac receives polio vaccination drops from health extension worker Guenet Zewdie.
©UNICEF Ethiopia/2010/Getachew
A clinic in Marmalade, Haiti has adopted the Clean Care standards. They have a team of people who take shifts cleaning the clinic.
Photo Credit: Karen Kasmauski/MCSP and Jhpiego
Title
•Dr. Schreiber of San Augustine giving a typhoid innoculation at a rural school, San Augustine County, Texas
Names
•Vachon, John, 1914-1975, photographer
Created / Published
•1943 April
Headings
•- World War, 1939-1945
•- Children
•- Rural schools
•- Physicians
•- Vaccinations
•- United States--Texas--San Augustine County
Notes
•- 12002-56.
•- Transfer from U.S. Office of War Information, 1944.
•- General information about the FSA/OWI Color Photographs is available at hdl.loc.gov/loc.pnp/pp.fsac
•- Title from FSA or OWI agency caption.
•- Additional information about this photograph might be available through the Flickr Commons project at www.flickr.com/photos/library_of_congress/2179909780 External
•- Published in: "Images of America" chapter of the ebook Great Photographs from the Library of Congress, 2013.
Source Collection
•Farm Security Administration - Office of War Information color slides and transparencies collection (Library of Congress)
Digital Id
•fsac 1a35422 hdl.loc.gov/loc.pnp/fsac.1a35422
•cph 3d02191 hdl.loc.gov/loc.pnp/cph.3d02191
LCCN Permalink
•https://lccn.loc.gov/2017878819
Temam Ahmed with his nine month old child Hamid at the Derer Ebija Health Post where they have come to get the newly introduced PCV vaccine.
©UNICEF Ethiopia/2011/Lemma
Hospital Corpsman Zarzeck gives H1N1 Influenza shots at BUMED, December 23, 2009. This photograph has been altered to obscure ID cards)
Pakistan, 2011: A health worker vaccinates an infant against polio during Polio National Immunisation Day (NID) in Sherpow in Landhi town, Karachi Pakistan. Twenty four new polio cases have been reported in 2011. The Ministry of Health, WHO, UNICEF and other partners are holding the Sub-National Immunization Days across Pakistan on April 5-7. For the countrywide polio effort, UNICEF is taking the lead on public advocacy, social communication and vaccine supply management.
1 April 2011
© UNICEF Pakistan/2011/Asad Zaidi
To learn more:
Rotary International advocacy visit to Ethiopia to support the polio eradication efforts and participate in the National Polio Immunization campaign in November 2014, where nationally, over 13 million children under the age of five will be vaccinated against polio. ©UNICEF Ethiopia/2014/Tsegaye
www.wsj.com/articles/covid-19-vaccination-delays-could-br...
Covid-19 Vaccination Delays Could Bring More Virus Variants, Impede Efforts to End Pandemic
Scientists say high rates of viral spread in a partially immunized population could encourage mutations that make virus harder to contain
Scientists say the world has reached a precarious point in the Covid-19 pandemic, one where conditions are ripe for the rise of more new coronavirus variants that could complicate efforts to control the disease.
The virus continues to spread rapidly in many parts of the world, even as segments of the population have gained some degree of immunity as a result of having been infected or vaccinated.
Scientists say that combination—high rates of viral transmission and a partially immunized population—encourages the emergence of variants that are potentially more transmissible or more lethal. More transmission means more opportunities for the virus to evolve, they say.
“If everyone has immunity, then you have pretty much no virus circulating and the virus can’t adapt,” University of Bern molecular epidemiologist Emma Hodcroft said, adding that if no one within a population has immunity, then there’s no pressure on the virus to evolve. “That middle part, where you have a partially vaccinated population, or a partially immune population with lots of virus circulating, that’s kind of your danger point,” she said.
New variants could also reduce the effectiveness of Covid-19 vaccines and treatments and lead to reinfections among people who have already recovered from Covid-19, scientists say. The key to minimizing these problems, they say, lies with social distancing and other measures to reduce contagion as well as with ramping up vaccination efforts, which have lagged behind in many places.
www.latimes.com/california/story/2021-02-20/vaccine-ledeall
More problems slow COVID-19 vaccine distribution in Los Angeles Vaccinations at Dodger Stadium
Los Angeles continued to struggle with COVID-19 vaccine distribution due to a variety of factors Friday as officials pushed forward with efforts to get underserved Black and Latino communities inoculated.
The city postponed more vaccination appointments scheduled for Saturday as vaccine shipments remain stuck in transit by winter weather that has hammered much of the country.
It was not immediately clear how many appointments were affected, but the delays will occur at the large-scale vaccination sites run by the city at Hansen Dam Recreation Area, San Fernando Park, Lincoln Park, Pierce College, Crenshaw Christian Center and Dodger Stadium.
Officials already pushed back 12,500 appointments scheduled Friday because of supply disruptions. City-run mobile vaccination clinics will continue to operate as scheduled.
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Officials said Thursday afternoon that the weather delays had yet to interrupt operations at vaccine sites run by L.A. County, which include the Pomona Fairplex, the Forum in Inglewood, Cal State Northridge, the county Office of Education, Six Flags Magic Mountain, Balboa Sports Complex and El Sereno Recreation Center.
The new postponements, which L.A. Mayor Eric Garcetti announced Friday, mark the latest fallout from the winter weather that has battered much of the country, with days of freezing rain, ice and snow that have knocked out power, grounded flights and created hazardous travel conditions.
The inclement weather has tied up two L.A.-bound shipments of the Moderna vaccine, totaling some 63,000 doses, that were supposed to be available for appointments this week and next, according to city officials.
The main manufacturing facilities for the nation’s two COVID-19 vaccines — made by Moderna and Pfizer-BioNTech — are in Massachusetts and Michigan.
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The state was anticipating stepped-up vaccine deliveries in the coming weeks, but that was before the winter storms struck. And those distributions still would have brought far fewer doses than what is needed to quickly work through the queue of people eligible to receive vaccines.
California — along with the rest of the country — has been contending with a scarcity of vaccines, with officials saying they have the capacity, but not the supply, to inoculate significantly more people.
A consistent challenge is that both available COVID-19 vaccines require two doses, administered three or four weeks apart.
Lately, the need to provide second shots has spurred officials throughout the state to greatly limit access to first doses.
Meanwhile, officials are ramping up efforts to get more vaccine to underserved communities.
“We’re seeing still disproportionately low vaccination rates among many of our Black and Latino populations and communities, a reflection not only of historic distrust and community trauma, but also the structural barriers that stand between too many Angelenos and their access to vaccines,” Garcetti said Thursday. “We need to tear those barriers down.”
His comments come after data showed that Black, Latino and Native American residents 65 and over were receiving COVID-19 vaccinations at a lower rate than their white, Asian American and Pacific Islander counterparts.
In L.A. County, Latinos are seeing 40 COVID-19 deaths per 100,000 residents a day and Black residents are seeing 20 deaths, compared with 14 deaths per 100,000 white residents a day.
Neighborhoods will be prioritized for mobile vaccination clinics using medical vulnerability indicators developed by UCLA researchers, including the incidence of preexisting health conditions, barriers to accessing service, environmental risks and social vulnerability.
Mobile vaccination services this week expanded to South Park, Green Meadows and Boyle Heights; in coming days, that will widen to include Chinatown, Vermont Square and Pico-Union, the city said in a news release. By the end of March, the city hopes to have additional sites in East L.A., South L.A., Northeast L.A. and the East San Fernando Valley.
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Am I eligible for California’s $600 COVID-19 stimulus check and other aid?
LOS ANGELES, CA - FEBRUARY 16: California Governor Gavin Newson addresses a press conference at a COVID-19 vaccination site established in a partnership between the federal government and the state opened today at Cal State Los Angeles, one of two in the state and the first phase of an effort expected to spread to 100 sites across the nation. The CSULA site is co-run by the Federal Emergency Management Agency and the state of California through the governor's Office of Emergency Services. The site is expected to have an ultimate capacity of administering 6,000 doses per day, although it opened Monday with just 3,000 doses. Gov. Gavin Newsom said, however, the site would reach the 6,000-dose mark by the end of the week at both the Los Angeles and a Oakland site. Shortages in supply have hampered vaccination efforts at county- and city-operated sites, but officials noted that the vaccines provided at the two FEMA sites will be in addition to the state's normal supply. "We're committed to ensuring that everyone who wants a vaccine gets one,'' FEMA Administrator Bob Fenton said during a news conference at the CSULA site. Fenton noted that the site was chosen specifically for its accessibility to hard-to-reach communities, "focusing on areas where minorities make up over 40% of the population, looking at other factors such as poverty, lack of housing or vehicle access.'' Cal State LA on Tuesday, Feb. 16, 2021 in Los Angeles, CA. (Al Seib / Los Angeles Times).
Rotary International advocacy visit to Ethiopia to support the polio eradication efforts and participate in the National Polio Immunization campaign. ©UNICEF Ethiopia/2015/Meklit Mersha
(Karen Kasmauski/MCSP). General scenes in the Maternity center at Tsafe General Hospital where immunizations, family planning, pre-and post natal care as well as birthing by midwives.
Josiane Pierre, a health worker, speaking to members of the community.
Photo Credit: Karen Kasmauski/MCSP and Jhpiego
Nurses weigh babies in a clinic in Marmalade, Haiti that has adopted the Clean Care standards.
Photo Credit: Karen Kasmauski/MCSP and Jhpiego
Rotary International advocacy visit to Ethiopia to support the polio eradication efforts and participate in the National Polio Immunization campaign in November 2014, where nationally, over 13 million children under the age of five will be vaccinated against polio. ©UNICEF Ethiopia/2014/Tsegaye
Rotary International advocacy visit to Ethiopia to support the polio eradication efforts and participate in the National Polio Immunization campaign. ©UNICEF Ethiopia/2015/Meklit Mersha
Women are immunized against cervical cancer and pap smears are conducted in the HPV Immunisation room. Bogota, Colombia. Instituto Nacional de Cancerología
Dr. Pascal Villeneuve of UNICEF, the chair of the Inter-Agency Health Donors Group (GIBS), emphasized the need for the government of DRC to continue to commit financial resources toward reaching unvaccinated children.
Dr Pascal Villeneuve de l’UNICEF, Représentant du Groupe Inter Bailleurs de Santé (GIBS) a insisté sur le besoin du Gouvernement de la RDC de continuer à mettre les ressources financières disponibles pour atteindre les enfants non vaccinés.
Photo by Kaukab Jhumra Smith/USAID
There have been no new cases of wild polio virus in the Democratic Republic of Congo since December 2011, a marked contrast from a high of 100 cases in 2010. World Immunizations Week, April 24 to 30, 2015, presented an opportunity to celebrate this exciting public health milestone and offered a chance to commit to reaching all the children who have not yet been vaccinated against preventable diseases. USAID contributes $3.5 million each year to polio vaccination efforts in the DRC through the World Health Organization (WHO), UNICEF and USAID’s Integrated Health Project. USAID also supports immunizations worldwide through direct support to GAVI, the Vaccine Alliance.
On April 28, 2015, in Mbankana, Kinshasa province, USAID officials joined the Prime Minister of the DRC, Augustin Matata Ponyo, the DRC Minister of Health, Dr. Felix Kabange Numbi, and representatives from GAVI and other international donors, at a ceremony at a newly built health center. The event honored DRC’s efforts to remain polio-free and launched a fleet of new refrigerated trucks for the safe transport of vaccines to remote areas of the country.
To reach a home of a 4-year-old P.Otgonjargal. Ms Oyunchimeg’s team traveled by jeep, reindeer, a rope-drawn ferry and foot. A team member examines the girl, who is accompanied by her mother. © UNICEF/NYHQ2012-1732/BRIAN SOKOL
Nasra Mohammed Sherifwith her 7 months child - Siham Mohammed after getting polio vaccine at Togwajale Health Center, Jigjiga, Somali Regional State ©UNICEF Ethiopia/2019/Nahom Tesfaye
British Rotarians take immunize children in the streets of Lucknow during a round of the polio immunization campaign in Northern India. .Rotarians Bernice Yates, Pam Joyce and Jackie Berry work at a polio vaccination booths on the first day of the campaign..The drive is part of the campaign to eradicate polio in India and target the high-risk area of Uttar Pradesh and Bihar. (photo Jean-Marc Giboux)
(Karen Kasmauski/MCSP). General scenes in the Maternity center at Tsafe General Hospital where immunizations, family planning, pre-and post natal care as well as birthing by midwives.
Isonail Kabiru, rt. and Badiru Halidu, are Male motivators who go into the community and talk to the men about family planning.
Official Launch of the Polio Sub-NID, at the India Islamic Center in Lucknow, Uttar Pradesh, with Mullana Khalid Rasheed and District Magistrate A.K. Ghosh and visiting british rotarians , on November 8, 2009 . (photo Jean-Marc Giboux)
Slum dwellers in Lucknow..India has been engaged in a campaign to eradicate polio in India which target the high-risk area of Uttar Pradesh and Bihar with polio immunization drives every 2 months. (photo Jean-Marc Giboux).
www.nature.com/articles/d41586-021-02532-4
COVID vaccine immunity is waning — how much does that matter?
As debates about booster shots heat up, what’s known about the duration of vaccine-based immunity is still evolving.
Six months ago, Miles Davenport and his colleagues made a bold prediction. On the basis of published results from vaccine trials and other data sources, they estimated that people immunized against COVID-19 would lose approximately half of their defensive antibodies every 108 days or so. As a result, vaccines that initially offered, say, 90% protection against mild cases of disease might only be 70% effective after 6 or 7 months1.
“It felt a little bit out on a limb at the time,” says Davenport, a computational immunologist at the University of New South Wales in Sydney, Australia. But on the whole, his group’s predictions have come true.
Immunological studies have documented a steady decline of antibody levels among vaccinated individuals2. Long-term follow-up of vaccine trial participants has revealed a growing risk of breakthrough infection3. And health-care records from countries such as Israel, the United Kingdom and elsewhere all show that COVID-19 vaccines are losing their strength, at least when it comes to keeping a lid on transmissible disease.
That’s without accounting for the Delta threat either — and it’s clear that vaccine–induced antibodies do a worse job at recognizing SARS-CoV-2 variants compared with the ancestral strain of the virus4. What remains unclear, however, is to what degree the immune system’s safeguards that protect vaccinated people against severe disease, hospitalization and death might be fading as well. “That,” says Davenport, “is the million-dollar question at the moment.”
As discussions over booster programmes heat up — with leading global-health authorities coming out publicly against the idea this week, UK officials endorsing boosters for the over-50s, and advisers to US regulators meeting on 17 September to discuss the issue — Nature takes stock of the data informing the debate.
How is vaccine-induced immunity holding up?
“Things wane,” says Nicole Doria-Rose, an immunologist at the US National Institute of Allergy and Infectious Diseases in Bethesda, Maryland. But not all things wane equally.
‘Neutralizing’ antibodies that can intercept viruses before they infiltrate cells might not have much staying power. Levels of these molecules typically shoot up after vaccination, then quickly taper off months later. “That’s how vaccines work,” Doria-Rose says.
But cellular immune responses are longer lasting — and as Jennifer Gommerman, an immunologist at the University of Toronto in Canada, explains: “Cellular immunity is what’s going to protect you from disease.” Memory B cells, which can rapidly deploy more antibodies in the event of re-exposure to the virus, tend to stick around, and so do T cells, which can attack already-infected cells. Both provide an added measure of protection should SARS-CoV-2 sneak past the body’s first line of defence.
In one of the only long-term studies to consider these three planks of the immune system simultaneously — antibodies, B cells and T cells — researchers found that vaccination spurred durable cellular immunity5. Memory B cells continued to grow in numbers for at least six months, and got better at fighting the virus over time. T-cell counts remained relatively stable, dipping only slightly over the duration of the study period.
“So, you have this reserve,” says John Wherry, an immunologist at the University of Pennsylvania Perelman School of Medicine in Philadelphia, who led the study. “Circulating antibodies may be declining, but your immune system is capable of jumping into action once again.”
How can immune memory actually be getting stronger?
Research from immunologist Ali Ellebedy, at Washington University School of Medicine in St Louis, Missouri, helps to explain the vigour of the memory-B-cell response. His group took samples from the lymph nodes of vaccinated individuals and found tiny B-cell finishing schools — called germinal centres — that were churning out ever more potent immune cells as time went on6.
B cells in these structures randomly mutate their genes to create entire new sets of antibodies. Those cells that produce the best antibody repertoires eventually win out through an evolutionary process that augments the immune system’s ability to fight off Delta and other SARS-CoV-2 variants of concern.
Ellebedy and his colleagues initially described the persistence of these germinal centres for 15 weeks post-immunization with an RNA-based jab — longer than anyone had ever seen before with older-technology vaccines for other ailments. Now, the researchers have unpublished data, following the germinal centres for up to six months. “The training camp is still going,” Ellebedy says. “It’s amazing.”
Should that immune memory give durable protection against severe disease?
For the most part, it should. But, says Theodora Hatziioannou, a virologist at the Rockefeller University in New York City, “if protection from disease relies at any level on circulating neutralizing antibodies” — and those molecules are clearly on the decline — “then, yes, the longer out you are from natural infection or from vaccination the worse you will be”.
Real-world data from diagnostic-testing records and hospital databases suggest that this might be the case. In Israel, for example, elderly people who got their shots at the beginning of the year seemed to have almost double the risk of severe illness during a July outbreak compared with similar individuals who were immunized more recently7. As researchers reported this week, older individuals given a third dose of vaccine were less likely to become infected and much less likely to develop severe disease than those who had not received the boosters8.
To Eran Segal, a computational biologist at the Weizmann Institute of Science in Rehovot, Israel, who advises the Israeli government on COVID-19 issues, the implications are clear-cut. “There’s compelling evidence that the third dose increases protection dramatically.”
But as University of Pennsylvania biostatistician Jeffrey Morris points out, inferences made from observational studies of this kind should be viewed with a critical eye. People going about their everyday lives are not clinical-trial participants. They are not randomized to account for behavioural and demographic differences. And although statistical modelling can help to correct for some of these variables, it’s impossible to account for all potential confounding factors.
“The bottom line,” Morris says, “is we need careful modelling and we need really thorough data to deconvolve all these things.”
What about other countries besides Israel?
Preliminary data from the United Kingdom and Qatar would seem to confirm the Israeli experience. Researchers at Public Health England posted a preprint this week detailing a modest but appreciable dip in vaccine effectiveness against hospital admission and death. This occurred about 20 weeks out from inoculation for recipients both of the mRNA vaccine from Pfizer–BioNTech and the viral vector vaccine from the AstraZeneca — although the effect was most pronounced for older individuals and those with underlying health conditions. Among the elderly, there was also some indication that spacing out the initial two doses of vaccine promoted more durable protective immunity.
Meanwhile, in Qatar, Laith Abu-Raddad and his colleagues described last month how the vaccine from Pfizer–BioNTech had provided consistently high protection against critical illness for up to six months post-immunization. Vaccine effectiveness against mild or symptom-free infections has declined gradually, as expected. But at the time that he posted a preprint online, on 27 August9, Abu-Raddad, an infectious-disease epidemiologist at Weill Cornell Medicine-Qatar in Doha, was unsure about the need for booster shots.
Then, he says, he saw the data from seven months post-immunization. Although the results are preliminary, the vaccine’s ability to ward off hospitalization and death seems to drop off. “The data now forced a change in thinking,” says Abu-Raddad. (A comparable study from the United States has so far reported data only on waning protection against infection, not severe disease10.)
Still, globally, there is as yet no indication that the rates of severe illness among the vaccinated are spiking in any appreciable way. “The vaccines are really designed to prevent disease,” says Julie McElrath, an infectious-disease specialist at the Fred Hutchinson Cancer Research Center in Seattle, Washington. “That is still holding up.”
Even if most vaccinated individuals are not getting really sick, are there other benefits to boosters?
Reducing rates of infection should help break the cycle of viral transmission, which would ultimately result in fewer cases of severe COVID-19 and death. And according to Fyodor Kondrashov, an evolutionary geneticist at the Institute of Science and Technology Austria in Klosterneuburg, it should also help keep the emergence of vaccine-resistant variants at bay.
“Things that are good from the epidemiological perspective,“ he says, “are also good from the evolutionary perspective.”
As Kondrashov’s modelling work has shown, resistant viruses are most likely to emerge when transmission is not controlled11. Getting more people vaccinated is the single most effective intervention to keep transmission rates low, but any bump in vaccine effectiveness can help as well.
So far, no human vaccine has been completely undermined by resistance in the way that many anti-infective drugs have, says Andrew Read, who studies the evolution of infectious diseases at Pennsylvania State University in University Park. “It’s eroded their benefits,” he says, but in ways that have been fixable with tweaks in vaccine design.
That’s not to say it won’t happen with COVID-19 vaccines. “We’re on new territory here,” says Read. The Delta variant took the world by surprise. Evolution — and our immunological responses — could have more surprises in store.
But any discussion around the need for boosters cannot be had in a vacuum. In addition to considerations of immune kinetics among the immunized, there are also issues of vaccine equity and availability to factor in. And as long as vaccinated people are staying out of hospitals and morgues, then to Katrina Lythgoe, an evolutionary epidemiologist at the University of Oxford, UK, theoretical arguments around vaccine resistance are secondary. “In my view,” she says, “apart from people who are particularly vulnerable, efforts should be directed to getting people, globally, vaccinated.”