Are COVID vaccines the reason coronavirus cases are dropping? Here’s what we know
For the last five weeks, coronavirus cases have been steadily declining in the U.S. following peaks likely spurred by holiday gatherings. Meanwhile, COVID-19 vaccination rates have been picking up pace.
The big unknown: Are the two trends connected?
Experts agree it’s too early to know if the small amount of vaccines administered relative to the U.S. population is responsible for the recent dip in cases, hospitalizations and deaths. It’s partly because COVID-19 vaccines do not prevent infection, but rather severe disease and death, meaning vaccinated individuals may still contract the virus and spread it to others.
Yet, studies show the curtains may be rising, making way for the shots and all their benefits to dance across the nation. Meanwhile, uncontrolled coronavirus outbreaks are creating problematic intermissions that continue to block the performance of a lifetime — at least for some.
“Unfortunately, we’ve let this virus spread extensively and are launching the vaccination campaign at the height of the threat,” Dr. Lauren Meyers, a professor of biology and statistics at the University of Texas at Austin, told The New York Times.
And infectious diseases experts say we won’t know when exactly case load and hospitalization data will reflect benefits from COVID-19 vaccination, or when life will gain some sense of normalcy.
“The reality is the vaccine is not a silver bullet. It’s obviously really important, but it’s not like, ‘Yay we have the vaccine, all our problems are solved,’” Dr. Benjamin Linas, an epidemiologist at Boston University, told WBUR in January. “If you want to get to a world where we can start to loosen [restrictions] over the summer or next fall, put your masks on and don’t take them off.”
However, new scientific information points in “a very favorable direction,” Dr. Anthony Fauci, the White House coronavirus adviser, said during a Wednesday COVID-19 briefing.
He said Pfizer and Moderna, the two companies behind the authorized coronavirus vaccines in the U.S., are measuring the amount of virus, or viral load, in the nasopharynx of people who became infected with the coronavirus after vaccination, as well as in unvaccinated individuals who don’t show symptoms.
Understanding the difference in viral loads in these two groups of people will help scientists learn whether vaccinated people can still spread the virus to others, and how well. Generally, the higher your viral load, the higher your chance of spreading your respiratory germs to others.
Israel has so far vaccinated the most people per capita in the world, injecting 78 COVID-19 doses per 100 individuals, compared to 16.7 doses per 100 people in the U.S., Fauci said during the briefing.
A non-peer reviewed study there found that the viral load drops four-fold in people who become infected with coronavirus 12-28 days after their first COVID-19 vaccine dose. “These reduced viral loads hint to lower infectiousness, further contributing to vaccine impact on virus spread,” the study published Feb. 8 said.
A separate study from Spain of 282 clusters of coronavirus infections found that higher viral loads in nasal swabs of infected patients were associated with greater risk of transmission. In other words, they were more contagious.
“Bottom line message … When your turn to get vaccinated comes up, get vaccinated,” Fauci said. “It’s not only good for you and your family and your community, it will have a very important impact on the dynamics of outbreaks in our country.”
Some experts say more attention on preventive behaviors such as mask wearing and physical distancing may explain why COVID-19 cases are dropping across the country, while others speculate infections may be going unnoticed as testing efforts shift to vaccination ones, McClatchy News reported.
As of Feb. 18, more than 41 million people have received their first COVID-19 vaccine dose, while 16.1 million have been jabbed with their second, final one, a Centers for Disease Control and Prevention tracker shows. That’s a total of 57.7 million doses administered in the U.S., or about 12.1% of the total population, NPR reported.
It may take months before the vaccines truly make a dent in coronavirus case load, but in the meantime, they will be preventing severe disease and death in the most vulnerable populations, experts say — a win in itself.
“We may get to the point where, even though the virus is still spreading, it’s just less deadly on a population level and policymakers feel comfortable relaxing some of the measures we now have in place to protect our health care systems and save lives,” Meyers of the University of Texas told the Times.
This story was originally published February 18, 2021 at 2:41 PM with the headline "Are COVID vaccines the reason coronavirus cases are dropping? Here’s what we know."
