COVID-19 Q&A: Why do vaccinated people get infected? Can they get long-COVID? –

COVID-19 infections after vaccination — also known as breakthrough cases — were at the center of numerous reader questions MLive received over the last week.

Readers asked how fully vaccinated people can get COVID-19, how people can get re-infected, if vaccinated people are protected against long-term COVID, and which vaccines are most effective in preventing breakthrough infections.

For starters, no vaccine is 100% effective at preventing COVID-19.

The available vaccines work to provide your immune system with the blueprints of SARS-CoV-2 so that your body is ready in case of infection. Typically, the immune system of a vaccinated person will kick-in to fight off the virus earlier than someone who is not vaccinated, which limits virus replication and its ability to spread to the lungs where it can cause more damage.

Fully vaccinated people are less likely to get COVID-19 than non-vaccinated individuals. If they get infected, they’re more likely to report milder symptoms, clear the virus faster and avoid hospitalization.

Between Jan. 15 and Oct. 5, breakthrough cases accounted for 7% of Michigan’s confirmed cases, or 38,571 out of 544,409 cases. They accounted for 9.5% of hospitalizations (1,412 out of 14,924), and 9.2% of deaths (574 out of 6,236).

Among the 4.95 million Michigan residents fully vaccinated during that time, 0.8% tested positive for the virus, 0.03% were hospitalized, and 0.01% died from COVID-19. The most severe cases among the vaccinated are typically older and/or have serious underlying conditions.

There isn’t a lot of data on re-infection rates, but there have been cases where people get COVID-19 a second time. That’s not unexpected, as the coronavirus has continued to evolve into new strains as its worked its way through the global population.

One study in Kentucky did find that non-vaccinated people were 2.34 times as likely to be re-infected compared to vaccinated individuals.

Long-COVID is another topic that needs more research, but a recent study published in the journal The Lancet found that vaccinated individuals had a reduced risk of developing long-term COVID-19 symptoms lasting more than four weeks, compared to non-vaccinated individuals.

It’s not yet clear if the severity of symptoms plays a role in who experiences COVID-19 symptoms for longer than 28 days, but there have been reported long-hauler cases among individuals with mild and severe cases of COVID-19.

Last month, the CDC shared a report comparing the effectiveness of the vaccines in preventing hospitalizations for COVID-19 among adults without immunocompromising conditions. The report, looking at data from March-August 2021, found the Moderna vaccine to be 93% effective, compared to the Pfizer vaccine (88%) and the Johnson & Johnson vaccine (71%).

That said, health officials have indicated that all three vaccines provide substantial protection against severe cases of COVID-19, at least in the short-term. They have all proven effective at limiting infections and reducing severe cases resulting in hospitalization and/or death, and booster shots are now being evaluated for each vaccine to determine who should get one and when.

Below are some of the additional questions we received this week, along with answers from our health reporters, based on previous and new reporting.

Q: If I have been vaccinated and later contracted COVID, what level of caution should I have after that? If I am a close contact now, can I still get and spread COVID to others?

Between your immunity from natural infection and the vaccine, you should have a robust protection against the virus. You’re increasingly less likely to get infected again, at least within the first 90 days. After that period, it’s possible you could be re-infected as the coronavirus continues to mutate into new variants, but your chances of developing severe illness have diminished.

Q: Has there been a study on those who had Guillain Barre syndrome and then received the COVID shot so I can be better prepared to make the decision to get vaccinated or not?

GBS is a rare autoimmune disorder in which an individual’s immune system damages the nerves, causing muscle weakness and sometimes paralysis. Its symptoms can last anywhere from weeks to years, and while most people fully recover, some have permanent nerve damage, according to the CDC.

Annually, an estimated 3,000 to 6,000 people develop GBS. Individuals are more likely to develop GBS from influenza than from the flu vaccine, but in very rare occasions people have developed the syndrome in the days or weeks after getting a flu shot, according to the CDC. That typically amounts to another 1-2 cases per one million flu vaccine doses administered.

Regarding COVID-19 vaccines, the FDA has noted an increased risk of GBS with the Johnson & Johnson vaccine after there were 100 cases reported within the first 12.5 million doses administered. The data is enough to show an association with the shot and increased risk for GBS, but not a causal relationship.

There has been no such increased risk found between GBS and the mRNA vaccines (Pfizer or Moderna), according to the FDA. Additionally, an Israeli study found that out of 702 patients with previous cases of GBS who received an mRNA vaccine for COVID-19, only one patient reported needing short-term medical care for relapse of a previous cases of GBS, “which represents a minimal risk,” according to the study. The patient was treated with plasmapheresis and showed significant improvement before being discharged from the hospital.

Q: My wife and I have both been vaccinated. We’ve heard that vaccinated people can still get COVID-19. We live in Livingston county and we are wondering when and where do we have to wear masks?

The CDC recommends that everyone wear mask while indoors with people outside their household in communities with “high” or “substantial” risk of coronavirus spread. All 83 Michigan counties are reporting 50 or more cases per week per 100,000 people and/or a positive test rate of 8% or higher, as of Wednesday, Oct. 20, which qualifies the entire state for that risk designation.

You can check out the CDC’s county-level transmission tracker, here. Once your county slips into the yellow (moderate) or blue (low) risk levels, the CDC says it’s OK for fully vaccinated individuals to take off their masks indoors.

Q: I have received first and second dose of Moderna vaccine. I am 82 years old with some heart issues. Is the Moderna booster vaccine available for me to receive?

A third-dose booster of the Moderna vaccine is available for some individuals with compromised immune systems. When the FDA amended the emergency use authorization language in August, it added that a third dose should be made available to organ transplant recipients “or those who are diagnosed with conditions that are considered to have an equivalent level of immunocompromise.” In Michigan, there have been 33,039 Moderna boosters administered as of Tuesday, Oct. 19.

For specific cases, it’s recommended that you speak with your doctor to gauge if your condition falls under that distinction.

However, the population eligible for a Moderna vaccine booster could soon expand. Last week, the FDA’s advisory committee of independent medical experts recommended the third dose be administered to any individual 65 and older, and to individuals 18 to 64 years old who are at high risk of severe COVID-19 and/or coronavirus exposure.

That recommendation will be considered by federal regulators in the near future. While regulators don’t have to listen to the committee’s recommendations, they have typically done so in the past as it relates to COVID-19 vaccines, and acted quickly on them.

Q: Recently the woman across the hall in our apartments died of COVID pneumonia. What’s our level of danger/exposure and should we notify everyone if we get COVID?

You’re considered a close contact if you’re within 6 feet of an infected person for 15 minutes or more over a 24-hour period. If you spent extended time with your neighbor indoors and without masks, you could be considered a close contact. But if you just passed by and occasionally exchanged greetings, you likely weren’t exposed.

The primary means of spreading coronavirus is through respiratory droplets. You should wash your hands after touching shared surfaces, but you’re not likely to become infected because of shared surfaces.

Q: Some church attendees want to resume singing without masks and social distancing. Is this safe considering the current rate of infection in Michigan? What about if everyone is vaccinated?

Singing has been considered a higher-risk activity, because respiratory particles can travel further when someone is singing loudly or breathing heavily versus when they’re talking or breathing. That risk is higher indoors and in settings without physical distancing.

The two key factors to consider are the level of transmission within your community, and the vaccination status of the members. If transmission is low and/or everyone is vaccinated, the risk of becoming a super-spreader event goes down. It’s still possible that someone is pre-symptomatic and could be contagious without knowing it, but the likelihood of significant spread throughout the group is lower than if members are not vaccinated.

Q: Have you looked into the history of long-term vaccine complications? It seems this is being used as a reason for many to not get vaccinated against COVID-19, but I’m not aware of any large scale negative effects from vaccines in history.

Problematic reactions to vaccines typically occur immediately, and even less common adverse reactions typically occur within two to three weeks. After a few weeks, the body has discarded the vaccine’s elements and thus you’re unlikely to see any additional effects.

Dr. Anthony Ognjan, an infectious disease doctor with McLaren Health Care in Macomb County, said there haven’t been any long-term effects from vaccines since at least 1950, when health officials began tracking reactions through systems like the Vaccine Adverse Event Reporting System (VAERS). Even before then, side effects were typically limited to the short term.

Q: How does the level of infectiousness compare between those with COVID who have been vaccinated, and those who haven’t been vaccinated?

This is an interesting question, but one that hasn’t been answered yet. It’ll take some time still before researchers have enough data to conduct a retrospective study. Health officials theorize that vaccinated people are less infectious because they typically have less viral load and can clear the virus faster, but more study is needed.

For more answers to reader questions, check out the first and second iterations of MLive’s COVID-19 Q&A segment. If you have a COVID-19 related question as we continue through this pandemic, please respectfully submit it to

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