How protected am I against the Covid variant JN.1?
In recent years, the general assumption has been that a Covid infection – or vaccination – would likely give you a few months of protection. But every time we get a new variant that is particularly adept at evading the immune system, like JN.1, that assumption is challenged.
JN.1 currently accounts for approximately 93 percent of cases nationwide, according to data from the Centers for Disease Control and Prevention. It's unusual for a single variant to account for almost all cases, but the dominance of JN.1 gives us a unique insight into the risk of reinfection for many people.
If you had Covid when cases rose in the summer, or if you got the updated vaccine in the fall, here's what you need to know.
If I had Covid in the summer, how much protection do I have now?
You may be vulnerable to reinfection if you were infected during the summer, when previous variants caused a rise in cases.
That doesn't mean you will definitely get sick. “You should definitely have some protection,” said Aubree Gordon, an infectious disease epidemiologist at the University of Michigan. Immunity is an individual cocktail that comes from the number of times you have been previously infected, your vaccination history, underlying medical conditions and more. People who are 65 or older, have a weakened immune system or have underlying medical conditions are generally at greater risk of reinfection, says Fikadu Tafesse, a virologist at Oregon Health & Science University.
If a person is exposed to the same variant or a very similar variant in the months following a bout of Covid, their body is often equipped to recognize and fight it before it can cause an infection. Scientists disagree on exactly how long that protection lasts, but estimates range from about two to six months.
But JN.1 has “many more mutations than we are used to seeing,” said Dr. Marc Sala, co-director of the Northwestern Medicine Comprehensive Covid-19 Center in Chicago. Therefore, people who have recently been infected with another variant, even one that was previously dominant, may become reinfected.
What if I get the booster in the fall?
A CDC report published this month showed that people who received the updated vaccines that came out in the autumn had 54 per cent more protection against a symptomatic case of Covid than people who did not get the shot. The vaccines are formulated to target XBB.1.5, an earlier variant, but still provide some protection against JN.1, said Ruth Link-Gelles, the study's lead author. “They are all very closely related,” she said.
But even though a vaccinated person is less likely to develop symptomatic infections, that person is still not fully protected against the virus.
That said, there's still “quite a lot of benefit” from the updated vaccine, he said. In particular, vaccines reduce the risk of severe disease and hospitalizations, he said. Experts particularly urged people aged 65 or over or with weakened immune systems to get vaccinated. If from the end of January, Only about 12 percent of eligible children and 22 percent of adults had received an updated vaccine, according to the CDC
For many people, the more immunity you've built up — through infection, vaccination or both — the milder your symptoms are likely to be, Dr. Gordon said. Some people can become infected with JN.1 and experience such mild symptoms that they don't even realize they are sick, she said. However, people with compromised immune systems or underlying medical conditions may still have strong symptoms.
And those who do become infected with JN.1 will likely be well protected as long as it remains the dominant variant. At the moment it shows no signs of slowing down.