Our COVID-19 vaccines passed their first tests with flying colors. They work incredibly well and help slow the spread of disease in countries where they are widely available. Now scientists turn to the next key question: How long will they perform as well?
In people with COVID-19 and then vaccinated, new research shows they likely work for years. This group has powerful memory cells in their bone marrow that produce new antibodies when needed. And they work so well that they can even block variants of the virus, studies show. These people may not even need boosters to stay protected for the long term.
Protection may be different for people who have been vaccinated but have never had COVID-19, said Michel Nussenzweig, an immunologist at Rockefeller University in New York. Le New York Times. The immune system responds to vaccines differently than to natural infection, so they might need boosters against the variants – even if they have strong and long-lasting protection against the original coronavirus strain. “That’s the kind of thing we’ll know very, very soon,” Nussenzweig said.
Fortunately, more research is advancing to determine exactly what these potential boosters might look like. Scientists are looking at the levels of antibodies a person needs to be protected from COVID-19. This benchmark, known as the immune correlate of protection, will give them an idea of the safe threshold – if a person’s antibodies drop below, they could be more vulnerable to infection again.
Focusing on that threshold does two things. First, it gives scientists a way to monitor the protection of people who have already been vaccinated. They can watch to see how long it takes for the antibodies to drop below and get a feel for when people might need that booster. Antibodies naturally decline over time, and they’re not the only protective measure (these long-lasting memory cells in the bone marrow are another, for example). But they do provide some insight into how immunity might change.
Second, having a threshold of protection opens up a shortcut for creating all of the necessary reminders against COVID-19 variants. COVID-19 vaccine trials have involved tens of thousands of people. They took months to unfold, as researchers had to monitor how often people with and without injections got sick. Once we have a good idea of the immune response that stops the infections, they can test the boosters – which are functionally the same vaccine, with small changes – in smaller groups of people. We already know that injections are safe, so all they need to do is check if the new version also pushes people’s immune systems above the threshold.
Together, this research describes a way to protect people from COVID-19 in the future. This is starting to allay fears that protection against the coronavirus will start to fade over time, putting communities at risk for outbreaks. The virus is tricky and the variants are a ball of a curve, but – luckily – the human immune system also has ammunition.
Here’s what else happened this week.
What revolutionary infections can tell us
Finding and analyzing the rare cases of COVID-19 in people who have been vaccinated can give us crucial information about the variants. But testing vaccinated people too often can also have drawbacks. (Katherine Wu / Atlantic)
Moderna says his COVID-19 vaccine is effective in adolescents
The vaccine could be the second vaccine available for those under 18 and the key to safely reopening schools in the fall. (Nicole Wetsman / The edge)
Half of all American adults are now fully vaccinated against COVID-19
The country reached this important milestone in less than six months. (Bill Chappell / NPR)
The United States may never meet the collective immunity threshold. It’s OK.
In places like the United States, where half the population has been vaccinated, the pandemic will slow down and cease to be a threat even without reaching the level necessary for herd immunity. (Erin Mordecai, Mallory Harris and Marc Lipsitch / Le New York Times)
We have bigger problems than the origins of COVID-19
Spending too much time discussing speculation about lab leaks is a distraction from the important steps governments need to take to end this pandemic and prepare for the next one. (Nicole Wetsman / The edge)
During a brainstorming session in late April, we discussed several ideas, including gift cards, direct payments, and free tickets to sporting events. My senior advisor, Ann O’Donnell, who has been with me since I joined Congress, hesitantly suggested the idea of a lottery. She almost didn’t mention it because of its apparent absurdity. “It’s a bit of a crazy idea, but …”
—Ohio Governor Mike DeWine wrote in Le New York Times on the decision to give $ 1 million to five vaccinated adults through a lottery.
More than numbers
To the people who have received the 1.8 billion doses of vaccine distributed so far: Thank you.
To the more than 168,927,298 people around the world who have tested positive, may your journey to recovery be smooth.
To the families and friends of the 3,509,402 people who have died around the world, including 592,938 in the United States, your loved ones are not forgotten.
Stay safe, everyone.