Here are some recent articles on Covid 19 that you may have missed.
How long does protection from coronavirus infection last? It’s most durable in those who have been infected AND who are immunized.
Coronavirus immunity lasts at least a year, two studies indicate
The New York Times (5/26, Mandavilli) reports, “Immunity to the coronavirus lasts at least a year, possibly a lifetime, improving over time especially after vaccination, according to two new studies.” In a study published in Nature, researchers found that among “people who had been exposed to the coronavirus about a year earlier,” memory B cells “persist in the bone marrow and may churn out antibodies whenever needed.” In the other study, posted on bioRxiv, researchers found that “memory B cells continue to mature and strengthen for at least 12 months after the initial infection.”
Here is the New York Times article:
May 26, 2021
Immunity to the coronavirus lasts at least a year, possibly a lifetime, improving over time especially after vaccination, according to two new studies. The findings may help put to rest lingering fears that protection against the virus will be short-lived.
Together, the studies suggest that most people who have recovered from Covid-19 and who were later immunized will not need boosters. Vaccinated people who were never infected most likely will need the shots, however, as will a minority who were infected but did not produce a robust immune response.
Both reports looked at people who had been exposed to the coronavirus about a year earlier. Cells that retain a memory of the virus persist in the bone marrow and may churn out antibodies whenever needed, according to one of the studies, published on Monday in the journal Nature.
The other study, posted online at BioRxiv, a site for biology research, found that these so-called memory B cells continue to mature and strengthen for at least 12 months after the initial infection.
“The papers are consistent with the growing body of literature that suggests that immunity elicited by infection and vaccination for SARS-CoV-2 appears to be long-lived,” said Scott Hensley, an immunologist at the University of Pennsylvania who was not involved in the research.
The studies may soothe fears that immunity to the virus is transient, as is the case with coronaviruses that cause common colds. But those viruses change significantly every few years, Dr. Hensley said. “The reason we get infected with common coronaviruses repetitively throughout life might have much more to do with variation of these viruses rather than immunity,” he said.
In fact, memory B cells produced in response to infection with SARS-CoV-2 and enhanced with vaccination are so potent that they thwart even variants of the virus, negating the need for boosters, according to Michel Nussenzweig, an immunologist at Rockefeller University in New York who led the study on memory maturation.
“People who were infected and get vaccinated really have a terrific response, a terrific set of antibodies, because they continue to evolve their antibodies,” Dr. Nussenzweig said. “I expect that they will last for a long time.”
The result may not apply to protection derived from vaccines alone, because immune memory is likely to be organized differently after immunization, compared with that following natural infection.
That means people who have not had Covid-19 and have been immunized may eventually need a booster shot, Dr. Nussenzweig said. “That’s the kind of thing that we will know very, very soon,” he said.
Upon first encountering a virus, B cells rapidly proliferate and produce antibodies in large amounts. Once the acute infection is resolved, a small number of the cells take up residence in the bone marrow, steadily pumping out modest levels of antibodies.
To look at memory B cells specific to the new coronavirus, researchers led by Ali Ellebedy of Washington University in St. Louis analyzed blood from 77 people at three-month intervals, starting about a month after their infection with the coronavirus. Only six of the 77 had been hospitalized for Covid-19; the rest had mild symptoms.
Antibody levels in these individuals dropped rapidly four months after infection and continued to decline slowly for months afterward — results that are in line with those from other studies.
Some scientists have interpreted this decrease as a sign of waning immunity, but it is exactly what’s expected, other experts said. If blood contained high quantities of antibodies to every pathogen the body had ever encountered, it would quickly transform into a thick sludge.
Instead, blood levels of antibodies fall sharply following acute infection, while memory B cells remain quiescent in the bone marrow, ready to take action when needed.
The experts all agreed that immunity is likely to play out very differently in people who have never had Covid-19. Fighting a live virus is different from responding to a single viral protein introduced by a vaccine. And in those who had Covid-19, the initial immune response had time to mature over six to 12 months before being challenged by the vaccine.
“Those kinetics are different than someone who got immunized and then gets immunized again three weeks later,” Dr. Pepper said. “That’s not to say that they might not have as broad a response, but it could be very different.”
WANT TO HAVE A VACCINE PARTY? FROM THE SAN ANTONIO REPORT
Vaccine is now available in smaller quantities and the Pfizer vaccine can be refrigerated for a month at normal refrigerator temperatures.
Dear COVID-19 Vaccine Providers,
DSHS wanted to provide you with some important updates and reminders.
The Food and Drug Administration (FDA) has updated Pfizer COVID-19 vaccine Emergency Use Authorization (EUA). There are two items to this update.
- Storage and Handling
Thawed Under Refrigeration
Thaw and then store undiluted vials in the refrigerator [2ºC to 8ºC (35ºF to 46ºF)] for up to 1 month. This is a change from the previous 120 hours.
- How Supplied
In addition to the current packages of 195 six-dose vials (1,170 doses), the Pfizer COVID-19 vaccine will also be available in packages of 75 six-dose vials (450 doses).
DSHS would like to remind all providers about the updated COVID-19 vaccine ordering process.
Providers can now place orders for smaller quantities of vaccine in VAOS. Please place orders by the number of doses per vial:
- Moderna: 14 doses per vial – Order in multiples of 14 doses; or 10 doses per vial – Order in multiples of 10 doses
- Pfizer: 6 doses per vial – Order in multiples of 6 doses
- Janssen/J&J: 5 doses per vial – Order in multiples of 5 doses
For help with ordering, check out the COVID-19 Vaccine Order Requests in VAOS job aid.
Please also keep in mind that with the increased shelf-life of the Pfizer COVID-19 under refrigerated temperatures, providers can order enough vaccine doses for both first and second doses at the same time.
Currently, deliveries of vaccine orders are taking approximately two weeks from the time orders are placed.
Lastly, please continue to report doses administered to ImmTrac2 within 24 hours. If providers need support with data entry, please contact DataEntry@soc.texas.gov to coordinate delivery of records to the Austin Data Entry Center. Please include the following details in your request: provider name; point of contact; email address; and phone number.
Thank you for your continued dedication and support in vaccinating Texans!
Texas Department of State Health Services
BUT THESE VIALS STILL HAVE TO BE USED UPON OPENING WITHIN 6 HOURS SO THAT YOU HAVE TO HAVE ENOUGH PATIENTS LINED UP TO MINIMIZE WASTING.