As new COVID-19 variants spread throughout the community, protection from previous infections and prior vaccinations is waning.
“That protection you get from a previous infection is short-lived,” said Dr. Tim Brown, an infectious disease expert at the East-West Center, during a livestream Monday with the Honolulu Star-Advertiser. “It’s good for the first three months, it’s half gone by seven to 10 months, and it’s totally gone after about a year.”
Brown cautioned that the fading protection also occurs with vaccinations.
“The protection of that initial round, those first two doses, those are pretty much totally gone,” he said. “They will still protect you against severe illness and death, and reduce your risk of getting severely ill and dying, but they’re not 80 to 90% like they used to be. We’re probably talking 40, maybe 50% protection against severe illness and death if all you had was the first series.”
Brown recommended staying up to date on boosters for an added layer of protection.
“If you got one of the boosters, you’re probably protected for about six months,” Brown said. “You’re protected for two or three months after the booster from infection at higher rates, although not at the 95% rates we saw in the early days, probably at 60 to 70%.”
Part of the waning protection is due to the constant mutation of the virus as it evolves. Brown said some estimate the subvariants stemming from the omicron strain, including BA.2 and BA.4, have led to over 500 different subvariants.
“They are evolving to get around the current immunity we already have, whether that immunity is from vaccination or that immunity is from previous infection,” said Brown. “The good news is that there’s no evidence these new variants are more severe in terms of the illness that they cause than previous variants.”
Variants of concern Brown addressed included XBB, BQ.1 and BQ.1.1, all omicron subvariants. He added that BQ.1 is now the “fastest growing variant in the United States.”
“The two we’re worried about right now are the BQ.1.1 and the BQ.1,” he said. “They are very immune-evasive. They basically are immune to the drugs we have traditionally been using for the treatment of COVID. Not Paxlovid, but the monoclonal antibodies.”
The strains also have been attributed to the recent increase in cases throughout Europe, which serves as a warning about an upcoming potential spread in the U.S.
“Europe in the past has been a bellwether for what is going to happen in the United States two or three months later,” Brown said. “The bad news is we’re seeing these waves across Europe, and that means that we’re probably going to see a wave here.”
He added that the “caveat for Hawaii, remember, is that we’re exposed to people from all over the world.”
For the immunocompromised, Brown recommended staying up to date on vaccinations and boosters while also taking precautions such as wearing masks, using at-home tests, practicing social distancing and securing quick access to Paxlovid in case of an infection.
“The new bivalent booster is really important because it has some BA.5 in it, it has some omicron in it, as well as some of the original COVID variants that actually can give you better protection against these new variants coming in, most of which are descendants from BA.2 or BA.5,” he said. “Especially for the older members of our community, the immunocompromised, anybody who knows they have a preexisting condition that could put them at great risk of COVID illness.”
Brown also addressed the recent rise in respiratory illness in children, which has led to overcrowding at several hospitals throughout the state.
Respiratory Syncytial Virus, or RSV, is a respiratory illness that infects the lungs and bronchioles, resulting in cold-like symptoms which can last for several days. Severe illness can occur for infants, small children and the elderly.
“RSV is a serious illness in children,” said Brown. “It’s actually a fairly common childhood infection, and it had disappeared for the last few years to a large extent because of COVID precautions.”
Hilo Medical Center spokesperson Elena Cabatu confirmed an increase in RSV among younger patients in September, but said cases have plateaued in October.
“This is not something that’s completely unexpected,” said Dr. Jessica Kosut from Hawaii Pacific Health during a press conference on Oct. 13 related to RSV increases. “We have a respiratory season here in Hawaii that tends to be a little later than what we see on the mainland.”
Email Grant Phillips at gphillips@hawaiitribune-herald.com.