How Does Obesity Affect COVID-19 Vaccine Effectiveness?

Obesity has been considered a global epidemic for years. The condition, characterized by excessive weight gain and body fat, is also associated with the development of several other health issues. In turn, these issues play a part in deteriorating your overall health, which is a concern during this time when COVID-19 is still prevalent.

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For more than a year now, the world has been greatly affected by the COVID-19 pandemic. With that said, people have slowly come back to their regular routine. It is due to the availability of vaccines that help combat the development of the virus.

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At the same time, several conversations regarding the effectiveness of these vaccines have popped up, especially among people who have pre-existing medical issues. Obesity is one of the conditions that have been looked at side-by-side with the effect of the COVID-19 virus. As a result, a debate has sparked on whether or not weight problems affect the effectiveness of existing vaccines.
There are varying opinions regarding this issue, and we hope to settle it once and for all. To do so, let us look at both sides of the conversation.

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Obesity Affects COVID-19 Vaccine Effectiveness
Obesity is a condition associated with a higher risk of diagnosis and progression of COVID-19. Adults who have excessive weight are said to be more likely to need acute care and admission to the intensive care unit, intubation, and mechanical ventilation upon the virus's progression. Moreover, some studies show that mortality rates due to COVID-19 are more prevalent among patients with obesity.

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The link between obesity and COVID-19 stems from the presence of low-grade inflammation among people with weight problems. Excessive weight increases the body's susceptibility to infections and dampens the immune system's response to infectious agents. Moreover, obesity plays a role in altering the viral life cycle. That's why the duration of viral infection is prolonged by five days in people with a higher BMI than those with a normal BMI.
Further studies also emphasized how obesity affects the effectiveness of other flu vaccines. It is said that it lowers the immune response of other vaccines, including influenza, hepatitis B, and rabies. For instance, a higher BMI is associated with a significant decline in influenza A antibody titers after 12 months. It suggests that obesity weakens the body's ability to build a protective immune response against the influenza virus. The association may be fueled by the fact that obese people have lower gut microbial diversity, which is linked to low vaccine effectiveness.
With that said, data regarding the relationship between obesity and COVID-19 vaccine effectiveness is still not widely available. However, it is easy for people to create that connection based on past studies on other vaccines for viral infections.
With the growing number of obesity cases globally, experts are pushing for the development of more efficient vaccination strategies for this demographic. For example, a higher or additional dose may be administered to them for complete effectiveness. It is also suggested that obese people be categorized as high-risk cases, similar to those with comorbidities such as diabetes mellitus, chronic cardiovascular disease, respiratory disease, immunocompromised states, or cancers.

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Obesity Doesn't Affect COVID-19 Vaccine Effectiveness
Again, there's still no conclusive data that proves that obesity reduces the effectiveness of COVID-19 vaccines. It is enough for people to debunk these claims. People also state the results of clinical trials with some of the available vaccines that may detest the link between excessive weight and vaccine effectiveness.
A Phase 3 clinical trial data, published by the US FDA, shows some statistics regarding the Pfizer and Moderna COVID-19 vaccines.
The Pfizer vaccine is said to be 95% effective in preventing COVID-19 among participants. Seven days after the second dose, vaccine effectiveness was 95.4% in people with obesity and 94.8% in people without obesity.
Similarly, Moderna resulted in 94.1% effectiveness in COVID-19 prevention, based on the data released. Fourteen days after the second dose, vaccine efficacy was 95.8% in people with obesity and 91.2% for people with severe obesity.
While studies found that antibody responses in obese people were lower seven days after receiving their second dose, it doesn't mean that the vaccine's effectiveness was reduced.
Yes, obesity can lead to a low-grade inflammation, which may hamper the immune system's response to a vaccine. However, it should not stop a person from getting the vaccine. There are still inconclusive findings stating that vaccines don't protect people with obesity.
In conclusion, there is still not enough data that can prove whether or not obesity reduces the effectiveness of COVID-19 vaccines. We need to remind ourselves that, even if it has been over a year, COVID-19 is relatively new. So, it makes sense that there's not much regarding it compared to other vaccines like influenza and rabies.
Again, due to the medical conditions associated with it, obese people can still be susceptible to the COVID-19 virus. An added layer of protection from the virus from a vaccine can help those vulnerable to develop the virus. So, it is still advised to get vaccinated as soon as possible.
With that said, being vaccinated is not enough. Obesity can still cause other medical problems aside from COVID-19. A healthy lifestyle helps to prevent any further complications from happening. This includes maintaining a healthy weight.
If you belong to the overweight or obese category, this is the best time to change that. Whether you are losing weight through traditional means (diet and exercise) or alternative solutions (bariatric surgery or weight loss balloon), you are giving your body an added guard from any health problems.