COVID-19 survivors may only need one vaccine dose, study finds

Survivors of COVID-19 may only need one dose of the vaccine to be fully protected, a new study suggests.

Researchers from the Fred Hutchinson Cancer Research Center in Seattle found that, in blood samples of people previously infected with the coronavirus, a single shot of the inoculation boosted antibodies and other immune system cells by up to 1,000-fold.

What’s more, the vaccine was found to protective against the South African variant of the virus, which is more contagious that the original strains. 

The results are consistent with those of several others that have been published over the last few weeks – suggesting that the right supply of vaccine doses could be freed up so that more people can be immunized more quickly. 

It comes as Dr Anthony Fauci, the nation’s top infectious disease expert, says the data of these studies look ‘impressive,’ and that, if  the analysis holds up, health officials may consider letting coronavirus survivors get one vaccine dose.

For the study, published on pre-print server medRxiv.org, the team looked at blood samples from 10 coronavirus survivors who donated plasma.

Each one had blood samples examined before and after a single dose of either the Pfizer-BioNTech or the Moderna vaccine.

Results showed a significant jump in the levels of two types of white blood cells – B and CD4+ T cell responses, which help mediate immunity.

There was also a 1,000-fold increase in levels of neutralizing antibodies.

‘[This is] a massive, massive boost,’ lead author Dr Andrew T. McGuire, an immunologist at Fred Hutchinson Cancer, told The New York Times. 

”It looks pretty clear that we’re boosting their pre-existing immunity.’

Researchers also examined whether the antibodies generated by the vaccine would neutralize the original strain from Wuhan, China, and the South African variant known as B.1.351. 

They found samples from all of the participants neutralize the original strain, the variant and coronavirus that caused the SARS epidemic in 2002-2003.  

The team says it’s not sure how long the booted level of antibodies will endure , but ‘hopefully, they’ll last a long time, McGuire told The Times.

The findings are similar to several studies, including one by the Icahn School of Medicine at Mount Sinai in New York that looked at 109 people after receiving coronavirus vaccine doses, 41 of whom were previously infected with the virus.

COVID-19 survivors had antibody levels 10 to 20 times higher after just one shot and about 10-fold higher after a second shot

In another paper, from the University of Maryland, researchers looked at the antibody responses of 59 previously infected healthcare workers who receive a single dose of the Pfizer or Moderna vaccines. 

The results showed that those who had had COVID-19 earlier in the pandemic had statistically significant higher levels of antibodies than those without, and ‘had a classic secondary response to a single inoculation’. 

With more than 28 million confirmed cases – and the CDC suggesting that actual figure is closer to 83 million – it could mean that vaccine doses are freed up for those who have never been infected. 

It comes as Fauci, the director of the National Institute for Allergy and Infectious Diseases, was asked about the findings on Good Morning America on Tuesday.

Fauci said the data are remarkable, but that the results need to be examined more carefully before federal regulators issue any guidance suggesting survivors receive just one dose. 

‘Superficially, looking at it, it looks really quite impressive that if you have gotten infected and then get a single dose of the vaccine that the response you get is extraordinarily high,’ he told George Stephanopoulos.

‘So when we look at all that data and analyze it…if it holds true, we’re always open to considering that in people who do get infected, that they may only need one dose. But you really want to look at the data first before you make any policy decisions.’

Currently, 43.6 million people  – 13.5 percent of the U.S. population – have received at least dose and 18.8 million – 5.7 percent- have received two doses.

The daily average of vaccinations has fallen to 1.2 million per day, but it still appears President Joe Biden will reach his goal of 100 million shots in arms in the first 100 days of his term.