A study from the New England Medical Journal (NEJM) is the latest in a slew of research showing that one dose of a coronavirus vaccine protects COVID-19 survivors as much as two doses of people who have never been infected.
“These findings suggest that a single dose of vaccine elicits a very rapid immune response in individuals who have tested positive for COVID-19,” said study co-author and noted Mount Sinai vaccineologist Dr. Florian Krammer.
“In fact, that first dose immunologically resembles the booster dose (second) in people who aren’t infected.”
But Dr. Anthony Fauci and US health officials have urged everyone to get two doses of vaccines made by Moderna and Pfizer.
So why not give people who have had COVID-19 just one injection instead of two?
An expert told DailyMail.com that now that the US has more vaccine dose available from three manufacturers, the process of testing people to see if they’ve had coronavirus before would likely just create a ‘bottleneck’ in the rollout process, rather than the delivery to protect more people faster.
People previously infected with coronavirus (yellow) had antibody levels 10 to 20 times higher after their first dose compared to post-first dose levels for people who had not received COVID-19 (blue), the Mount Sinai researchers found.
At least 29 million Americans have already had coronavirus.
Giving them just one injection instead of two could mean an additional 29 million doses for the hundreds of millions of Americans who have never had the virus and developed immunity to it – or enough to fully vaccinate 14.5 million people.
The scientists behind the new study, which was published Wednesday, also think their research may shed some light on who is likely to have a more dramatic response to vaccines, and why.
Dr. Krammer, Dr. Viviana Simon and their colleagues studied a total of about 240 people.
The first group was made up of 109 people, about half of whom had coronavirus antibodies in their bloodstream, meaning they had been previously infected and developed some immunity to the infection.
Antibodies start to form in anyone who receives a first dose of COVID-19 vaccine, but it usually takes weeks to peak after the first dose, and a second dose is still needed to bring antibodies to an optimal protective level .
In the study, participants who previously tested positive for COVID-19 had 10 to 20 times higher levels of antibodies in their blood within a few days of their first dose.
By the time they got their second dose, the group’s antibody levels were 10 times higher than those who had not been previously infected (but had also had their second injection).
In other words, coronavirus survivors had about the same level of immunity after a single dose as people who had never had coronavirus but received two doses of vaccine.
Just as the first dose acts as a ‘prime’ for covid-negative people, the scientists suspect that earlier infection fires up the immune system and the second dose fires it up fully to fight coronavirus infection.
People whose immune systems were already ‘prepared’ to respond to coronavirus as a result of a previous infection (yellow) were much more likely to experience side effects from the injections – especially systemic effects such as fatigue, headache, fever and muscle or joint pain
The study also provided a possible clue as to why some people don’t have significant reactions to COVID-19 vaccination, while others are left with red welts and painful arms and can lie for days after the second injection.
The 83 COVID-19 survivors in a subgroup of 231 study participants were much more likely to experience arm pain, swelling, and redness, as well as more systemic effects such as fatigue, headache, chills, fever, and muscle or joint pain.
Does this mean that people with severe reaction to the shot would have had COVID-19 before, possibly without even knowing it? Not necessarily, but this may be the case for some.
Researchers at Mount Sinai went so far as to suggest that screening potential vaccine recipients for antibodies to the coronavirus could increase the supply of vaccines and reduce the number of people with more significant side effects.
“If the screening process determines the presence of antibodies as a result of a previous infection, a second injection of the coronavirus vaccine may not be necessary for the individual,” said Dr. Simon.
“And if that approach translated into public health policy, it could not only expand the limited vaccine supply, but also control the more frequent and pronounced responses to those vaccines in COVID-19 survivors.”
The UK preceded the US in the early days of their respective introduction of vaccines. Britons were initially given injections faster, thanks to several factors, including the fact that they had previously approved vaccines and had a more cohesive logistics system (in a smaller country).
But the nation also took a one-dose-first experimental approach, allowing Britons to delay their second dose of Moderna or Pfizer shots for up to 12 weeks, instead focusing on getting a first dose and some protection for as much as possible people, as soon as possible.
US officials have rejected this program, despite mounting evidence that a single dose provides significant protection.
And now the plan proposed by Dr. Simon may have missed its chance to be useful.
“ Now we are on our way to having enough supplies … so I wouldn’t think the FDA would be inclined ” to embrace the plan suggested by the findings of the Mount Sinai team, president of the Center for Medicine in the Public Interest Peter Pitts told DailyMail.com.
States are scheduled to receive 15.8 million doses of vaccines from Moderna and Pfizer this week.
Demand among eligible people that exceeds supply is less and less of an issue.
And Pitts is concerned that the strategy of screening people for antibodies before being vaccinated could further slow down the process of getting doses into the arms, which is already a significant barrier.
Referring to twentieth-century journalist and satirist HL Mencken, Pitts said, “For every complex problem, there is a simple solution that is wrong;” I think Mount Sinai scientists fell into that trap because it would create a huge bottleneck. ‘