MILWAUKEE - Health officials are strongly advising people get back to wearing masks in indoor public places. That is because the latest COVID-19 variants are the most contagious to date.
"One of the unique things about BA.5 is that it has immune evasion. So whether it’s from previous infection, or from vaccine, it can avoid that immunity you developed and still give you that breakthrough infection," said Dr. Ben Weston, Milwaukee County Chief Health Policy Advisor.
But the doctor said shots are still important.
"What the vaccine and booster still do for BA.5, which is most critical, is prevent that severe disease and death. So it’s still so important to be vaccinated and be up-to-date on your boosters," Weston said.
Dr. Ben Weston
Infectious disease doctors explain why the BA.5 strain is evading prior immunity.
"When you change the spike protein, it may change the ability of the virus to be recognized by prior immunity, because when you are making antibodies against the virus, you are making it against spike protein. So now if this one has a totally different spike, you having been infected by a previous SARS COV-2 may not protect you. And with the vaccine, because they are of course specific to spike proteins, if there’s enough change in that spike protein, previous immunization may not protect you from these new variants that arise," said Dr. Mary Beth Graham, Froedtert's Medical Director of Infection Prevention and Control.
Dr. Mary Beth Graham
In April, doctors first found the omicron subvariant BA.5 in South Africa. Dr. Weston said in that country, it did not spark lots of hospitalizations and deaths, but it did in Portugal.
Nationwide, the United States has seen a doubling of COVID-19 hospitalizations since April – though deaths remain steady.
"We do know that they are spreading fairly quickly, very efficiently, between people," Dr. Graham said. "For the state of Wisconsin, we are seeing still significant spread, but much fewer hospitalizations."
"BA.5 is far more transmissible than anything we’ve seen yet. So activities that were safe a month ago, 6 months ago, 2.5 years ago are not nearly as safe today because you’re much more likely to catch this virus," warned Weston.
One question you may have is if you should get a booster shot now or wait until the fall – when the federal government expects a booster targeting omicron variants.
"Take those precautions, too, if you’re in those risk factors, in those demographics that have higher risk of complications, please be up-to-date with your vaccination, and please consider those additional mitigation factors," Dr. Graham said.
"Our disease burden is going up. So this is a critical time to get yourself protected to the maximum extent possible, which means being vaccinated and boosted," Dr. Weston said.
What about masks?
"The vaccine and the booster isn’t providing quite as strong a shield against infection in the first place, as we’ve seen in the past. So when you’re indoors, when you’re in public, it's critical to wear these high quality masks, more so than in the past," Weston said.
In January, Milwaukee County reported COVID-19 patients were using 27% of hospital beds. Now it is down to less than 5% – though it is ticking up.