Kelley Parker, center, gives a report Friday to Dawn Cormier, right, on an incoming patient at St. Mary’s Regional Medical Center’s Emergency Department. In the case of suspected COVID-19 patients, staff would be protected by full personal protective equipment, including masks, eye protection, gowns and gloves. Masks are worn by everyone in the Lewiston hospital. Andree Kehn/Sun Journal

It’s been a dizzying few weeks of the pandemic.

Not even a month ago, it appeared the state’s high vaccination rate was paying off and Mainers might have a shot at a “normal” summer — as normal as it could be during a pandemic. Progress on the vaccination front had slowed to a crawl, but the rate of new daily infections in central and western Maine hit lows not seen since last fall in the days before the winter surge took off.

Within a matter of days, however, cases began to climb again, not just in the region, but across the state and the country. The Maine Center for Disease Control & Prevention late last month instituted a new recommendation that all people, regardless of vaccination status, wear a mask in areas of higher infection rates.

The U.S. CDC said “breakthrough” cases among vaccinated people were on the rise, and last Thursday, hours after Gov. Janet Mills announced that all health care workers in the state must be fully vaccinated by Oct. 1, the U.S. Food and Drug Administration approved vaccine booster shots for immunocompromised people.

Mainers have been asked to stay on their toes for the past 17 months, constantly adjusting to the virus’ spread in their communities and public health recommendations. The latest surge in cases — and its impact on Mainers’ daily lives — has left some wondering: Why didn’t the vaccines prevent this, and where does that leave us?

What is different about this surge? How did this happen if Maine has the third-highest rate of fully vaccinated residents in the country?


Simply put: the delta variant.

“Viruses have one goal and that’s really to survive,” said Joanne Kenny-Lynch, Central Maine Healthcare’s system director of infection prevention. “That’s it. They don’t think they’re just a bunch of googly-goop genetic material stuck in a capsule.”

Kenny-Lynch has worked in health care for 30 years and is trained in clinical microbiology and infection control. She currently works with a team of microbiologists and nurses to prevent infections of any kind within the hospital system, “including among patients, visitors and team members, and from equipment,” she said.

“We do a lot of education based on professional and scientific guidance and monitor for compliance to keep everyone who enters our four walls safe from developing or spreading infection,” she said, noting the more of the virus that is circulating in a community and jumping from person to person, the more opportunity it has to mutate and “evade host defenses.”

Cases of the variant in Maine exploded in July, according to data from the Maine CDC, from about 4% of cases sampled in June, to 86% in July. When cases began rising in Maine following the Thanksgiving break last fall, the delta variant may not have even existed — it was first identified in India in December.

In other words, the virus we’re seeing now is different than the one we saw in previous surges. Research cited by the U.S. CDC published last month said the delta variant is much more contagious and may cause more severe illnesses.


Meghan Lynch, a laboratory assistant, prepares nasal swabs for COVID-19 testing Friday at Central Maine Medical Center’s lab in Lewiston. The hospital tests between 50 and 75 samples from patients daily. Andree Kehn/Sun Journal

How much more contagious is the delta variant than the original strain or previous variants?

The delta variant is roughly twice as transmissible as other strains of COVID-19.

In basic epidemiological terms, one measure of how likely it is to spread is its basic reproduction number, or R0 (“r-naught”), which estimates the number of people to whom an infected person can transmit the disease.

The R0 of the original strain of the COVID-19 virus is 2 to 3, meaning that a single infected person will spread the virus to two or three other people. Seasonal influenza and the common cold have reproduction numbers between 1 and 2. Polio’s R0 is 5-7, while chickenpox is 9-10.

Measles, which is extremely contagious, has a reproduction number of 12-18.

The delta variant has a reproduction number between 5 and 9.


Eleanor Murray, an epidemiologist at Boston University, told The Atlantic’s Ed Yong that that number is “shockingly high.”

“Its reliance on super-spreading events basically goes away,” Samuel Scarpino of the Rockefeller Foundation told Yong.

Think of it another way: You know those plant burs that stick to your feet when you walk outside with your socks on? If the original COVID-19 strain is a small twig that occasionally gets stuck, the delta variant is one of those pesky burs that not even the washing machine can unstick.

The big picture, Kenny-Lynch said, “is to get the vaccination to get the number of people who are infected in our communities down and stop the mutation of the virus.”

Vaccines provide protection to yourself and those around you, “but if this thing keeps spreading around, we’re going to see some really funky other variants potentially come out.”

Why does the U.S. and Maine CDCs recommend that even fully vaccinated people wear masks in areas with higher transmission rates, and how do I know if that applies to me?


Vaccinated people may be as likely to transmit the disease to others as unvaccinated people, the U.S. CDC said last month.

“Why did the U.S. CDC shift its recommendations? Well, it’s that last point that explains this update,” Maine CDC Director Dr. Nirav Shah said at a briefing July 28, where he announced that Maine would follow the U.S. CDC’s masking recommendations.

“Specifically, (it’s) the risk that you could unknowingly, inadvertently spread the virus to someone, even though you yourself are fully vaccinated,” he said.

The likelihood of a person getting the disease from someone with a “breakthrough” infection — an instance in which a person two weeks out from their final vaccine dose contracts COVID-19 — is a “rare phenomenon, and the risk of this happening is thankfully low, but it is not zero.”

Masks add another layer of protection for everyone in areas where there is a high incidence of the virus and slows the further spread of the virus.

“The whole goal is to get that level of transmission and level of it moving through our communities down,” Kenny-Lynch said. “And by wearing a mask, you’re protecting yourself (and) everybody around you (by) you potentially not spreading it.”


Maine suggests that all people, regardless of vaccination status, wear a mask in indoor, public settings in counties with substantial or high levels of community transmission. The state keeps an updated list of counties where the masking recommendations are in place at

If I can still get COVID and spread it to other people, why should I get vaccinated?

Vaccines provide an immense amount of protection against contracting the virus, and significantly lower the risk of hospitalization or death from COVID.

The vast majority of those hospitalized with COVID-19 now are unvaccinated individuals, Shah said.

Since the first date that Mainers could be fully immunized, there have been 863 confirmed breakthrough cases as of Aug. 13. That means about 98% of the 37,993 individuals with a confirmed case of COVID-19 in that time period were unvaccinated.

Of the 852 hospitalizations in the same time period, 35 were vaccinated individuals, or 4%. There have been 237 deaths due to complications from COVID-19, 14 of which were among vaccinated individuals.


Friday’s report from the Maine CDC included an additional 151 breakthrough cases from the week prior. As of the same day, 824,626 Mainers have completed their inoculations.

An increase in the number of breakthrough cases is somewhat to be expected as the number of vaccinated people also increases, public health experts have said, but that shouldn’t discourage people from getting their shots.

Preliminary research has shown that all three of the vaccines authorized for use in the U.S. — Pfizer-BioNTech, Moderna, and Johnson & Johnson — maintain a high level of protection against the delta variant.

“Vaccination is our best hope of controlling the continued transmission in our communities,” Kenny-Lynch said, adding it’s the best way to stop the virus from mutating into a new strain that is vaccine resistant.

“We don’t want to frighten the public, but we want to make sure they understand that we have 93 million people in this country who are eligible to be vaccinated, who are not vaccinated,” Dr. Anthony Fauci , director of the National Institute of Allergy and Infectious Diseases,  told NBC News’ Lester Holt on Thursday.

“If you allow the virus to freely essentially roam through the vulnerable population and infect people, you give it ample opportunity to mutate, which means a person who’s unvaccinated is not only putting themselves at risk and their family, but really putting the community at risk.”


Who is eligible to receive a COVID-19 vaccine booster shot, and why are they necessary?

The FDA on Thursday night authorized third shots of the Pfizer and Moderna vaccines for immunocompromised people who have received a solid organ transplant or have certain cancers or other disorders. The U.S. CDC’s Advisory Committee on Immunization Practices unanimously endorsed the move Friday.

These are individuals who already had a lesser response to the vaccine due to a weakened immune system.

“How well you react to a vaccination depends on the vaccine itself, but also on your own body’s ability to react to the vaccine and have your immune system react to protect you,” Kenny-Lynch said. “If your immune system isn’t working well before you get the vaccine, it may not be able to provide you the full claim of infection.”

About 3% of the U.S. population will be eligible to receive a booster shot, and the FDA is not yet considering booster shots for the general population. The U.S. CDC published guidance for immunocompromised people and a list of conditions that qualify for a booster shot at

Should I get a shot of the Moderna or Pfizer vaccines if I got the Johnson & Johnson vaccine?


The FDA and U.S. CDC do not recommend that, or at least not yet. While studies are ongoing, there is not enough research on the potential risks that adding a Moderna or Pfizer shot to a J&J vaccine could have, or how it should be administered.

The good news is that the J&J vaccine offers a high level of protection against moderate to severe illness, and a recent study out of South Africa showed that it was effective against the delta variant.

All three of the vaccines, especially when combined with other protective measures such as masking and social distancing, lower the risk of developing a symptomatic case of COVID-19.

And the best level of protection comes from boosting vaccination rates, especially since children under the age of 12 cannot yet get vaccinated, and people with weakened immune systems do not have the same level of protection as others.

“There is history and precedent on our side,” Fauci said.

“If you look back at the history of devastating disease and epidemics — smallpox, polio, measles — what (was) the solution to that, it was universal vaccination. If we had an attitude of people not wanting to get vaccinated, we may not have eliminated polio from our society. You’ve got to have people appreciate that this is a common enemy. It’s the virus.”

This story was updated to correct the number of overall hospitalizations since the first date that Maine residents could be fully vaccinated, and added the U.S. CDC’s guidance on booster shots for immunocompromised people.

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