For more than two years, closing schools and offices, practicing social distancing, and wearing masks have kept Americans free from the flu and most other respiratory infections. This winter may be different.
With few to no restrictions and travel and socializing back in full swing, an expected increase in winter Covid cases appears poised to collide with a resurgent flu season, leading to a third It causes “twin demic” and even “triple demic” by pathogens. , respiratory syncytial virus, or RSV.
Influenza cases are starting to rise earlier than usual and are expected to spike in the coming weeks. Children infected with RSV (with flu and Covid-like symptoms), rhinoviruses and enteroviruses already get nervous pediatric hospital in some states.
Dr. Alpana Wagmere, an infectious disease specialist at Fred Hutchinson Cancer Center and a physician at Seattle Children’s Hospital, said:
Most cases of Covid, flu and respiratory syncytial virus are likely to be mild, but together they could sicken millions of Americans and swamp hospitals, public health experts say warns.
“This Covid immunity is weakening, consistent with the impact of the flu and RSV coming up here,” said Andrew Reed, an evolutionary microbiologist at Penn State University. in the realm.”
Covid and flu vaccines may not prevent infection, but offer the best protection against severe illness and death, experts say. They urged everyone, especially those at high risk, to get vaccinated as soon as possible.
Older people, immunocompromised people and pregnant women are most at risk, and young children are highly susceptible to influenza and respiratory syncytial virus. Many of the infected children have been compromised or had not been exposed to these viruses prior to the pandemic, so they have little or no immunity, so they are more severely ill.
Dr. Diego Hijano, pediatric infectious disease specialist at St. Jude Children’s Research Hospital, said: .
“It’s going to be a hard winter,” he said.
Another covid wave?
Coronavirus cases are low, but have started to rise in some parts of the country. Several European countries, including France, Germany and the UK, are seeing increases in hospitalizations and deaths, and experts fear the US will follow suit, as in previous waves. .
People with weakened immune systems “are still at risk even after receiving all the recommended vaccines and even boosters,” Dr. Waghmare said.
Public health experts are particularly concerned about a constellation of Omicron subspecies that appear to evade immunity from vaccines and even recent infections better than previous subspecies.
The latest booster vaccines made by Pfizer and Moderna are designed for the strains that circulated this summer, but not for these new strains. Still, they should help raise antibody levels overall, stave off severe symptoms, and shorten the duration of illness, said Aubrey Gordon, an epidemiologist at the University of Michigan.
The BA.5 variant was the most immune-evading variant until recently, but it is rapidly being replaced by other variants, including two that show even greater ability to evade immunity.
One of them, known as BQ.1.1, is a likely candidate to trigger the winter wave and is already experiencing a spike in cases across Europe.Together, he and a closely related variant called BQ.1 account for only about 11% of U.S. cases, but their share is rapid growth Up from just 3% two weeks ago.
A combination of two Omicron variants, called XBB, has caused a series of cases in Singapore, one of the countries with the highest vaccination coverage in the world. A subvariant of that, XBB.1, arrived in the United States. Another variant called BA.2.75.2 also immune evasion and cause more serious illnessbut so far it is responsible for less than 2% of cases nationwide.
Most of the other variants don’t appear to cause more severe symptoms than previous versions of the virus, but the immune evasion trend is likely to continue, experts say.
Cornelius Roemer, a computational biologist in Richard Neher’s group at the University of Basel, said:
The Food and Drug Administration certified booster Designed for BA.5 for all Americans ages 5 and up, so far only a small percentage of them qualify for the shot. received oneLess than 1 in 3 children between the ages of 5 and 11 have even completed their first dose of the Covid vaccine.
That may change as people witness a rapid rise in cases, Dr. Gordon said.
bad flu season signs
Before the coronavirus hit the world, the flu virus hit millions and killed tens of thousands of Americans every winter.in the 2018-2019 seasonInfluenza was responsible for 13 million medical visits, 380,000 hospitalizations, and 28,000 deaths.
In the Southern Hemisphere, the flu season is usually May to October, and in the Northern Hemisphere it is more likely in winter.The flu hit a few weeks earlier than usual this year. Australia and New Zealand, and the number of cases and hospitalizations was significantly higher.
Dr. Gordon tracks flu incidence among Nicaraguan children. In Nicaragua, he has one flu season in June and he in July, with a bigger season coming in late fall. Over 90% of the population considered him fully vaccinated against Covid by January 2022, and many said he had immunity from one or more infections. .
Still, the country had high rates of both Covid and influenza in the first half of the year. taller than More than during the 2009 flu pandemic, children were on average worse off than the previous year. “We saw a lot of hospitalizations,” Dr. Gordon said.
In the United States, flu typically begins in October, lasts through March, and peaks from December through February. But in some states, the season has already started this year.
About 3% of national tests be positive According to the CDC, as of October 8, the flu rate is over 10% in some southeastern states and over 5% in the south-central region.Percentage of tests positive for influenza in Texas jumped to It rose to 5.3% in early October from 3.7% the week before.
Public health experts have urged Americans, especially those at high risk, to get flu shots before cases rise significantly. Like the Covid vaccine, the flu vaccine may not exactly match the circulating variant, but still roughly speaking Cut your risk in half of hospitalization for both children and adults.
Antibodies take effect about two weeks after vaccination, so the current vaccine may actually provide more protection through the winter wave than the one received in September.
A CDC analysis found that last year’s flu vaccination coverage declined slightly across all age groups compared to the previous year. Her high-risk 6-month to her 4-year-old immunization rates showed the greatest decline. 75% to 67% before the arrival of coronavirus.
The low infection rate may be due to distrust of the COVID-19 vaccine spilling over into distrust of the flu vaccine, or simply parents forgetting the dangers of the flu to young children. It’s too early to tell if this year’s numbers will improve.
Older people and those with weakened immune systems should be vaccinated against both Covid and the flu, according to public health experts. You may want to choose both vaccines if you cannot afford to rest, or to protect those around you who are at high risk.
Some communities are at increased risk of severe illness and hospitalization from influenza. According to a published CDC report, during the 2009-2022 flu season, hospitalization rates were 80% higher for black adults, 30% higher for American Indian/Alaska Native adults, and 30% higher for Hispanic adults compared with white adults. was 20% higher at this week.
Influenza vaccination rate still It was much lower in these groups.Vaccination rate also decreased by about 9 points from the previous year pregnant Women of all races and ethnic groups.
In February 2020, Dr. Gordon was preparing to talk about the coronavirus in his 7-year-old daughter’s class when a boy in his class died of influenza B virus infection.
Dr. Gordon said of the flu: 例文 There is a vaccine that is effective against influenza, so I recommend that you get vaccinated.