The Side effects of COVID Vaccines

In my last blog, I had looked at the vaccines that are either available or will be available soon. I had indicated that I would touch on the side effects of the vaccines in this blog.

Earlier, in my book on COVID-19, I had indicated there are 4 phases of clinical trials on the suitability of a vaccine. In the first phase, the testing on humans is carried out to determine the optimum dose that is both effective as a vaccine and without serious side effects.

Moderna vaccine

In the first phase of the Moderna vaccine trial, one recipient had severe side effects. His arm became more painful during the second dose. After about eight to ten hours, he had chills and the temperature went up to 103.2 degrees. His fingertips felt cold. He was nauseous and his muscles hurt.

He went back to the urgent care where he was followed up. His temperature had come down and was given Tylenol. Instead of getting admitted as advised, he went home. His fever had risen to 101.5. When he got up to go to the bathroom, he felt nauseous again and vomited and fainted on his way back from the bathroom. He was asked to come back to the urgent care, but he chose to stay at home and by the evening of the second day, his fever came down and in a few days’ time he had no side effects.

The most common side effects were fever and pain in the injected arm. Other severe side effects included fatigue in 9.7% of participants, muscle pain in 8.9%, joint pain in 5.2%, and headache in 4.5%. Let us now go to the Oxford vaccine.

Oxford vaccine

In the race to come out with the first effective vaccine, Oxford was the leader. It already had a tested vaccine for another corona virus. They were held up a bit to identify a manufacturing partner, which later was Astra Zenca. The study was carried out primarily in four countries, namely the UK, Brazil, South Africa and the US and additionally in India.

The Oxford trial also faced an additional problem. There was a mix up of the doses provided by the manufacturer. While they thought that they were injecting the full dose vaccine, later they found out that the dose was only half. Interestingly when they analysed the results, they found that the half dose patients had less side effects and the efficacy was also over 90%. This mix up had to be studied in detail before proceeding further.

As the race continued, the Oxford study faced one major side effect in one individual. He had transverse myelitis a neurological condition. Until independent experts assessed the cause of the side effect, the study had to be stopped for a few days. As a result of this delay, they could not start their phase three trial in the US as planned and it is not over yet. In the meantime, Pfizer and Moderna completed their research and made their products available for use and so Pfizer received the first approval in the US.

Across all four studies, the Oxford vaccine had a good safety profile with serious adverse events and adverse events of special interest balanced across the study arms. The findings of their research were published in the Lancet, world’s leading scientific journal from the UK.

Serious adverse events occurred in 168 participants, with 175 events, three of which were considered possibly related to either the experimental or a control vaccine. A case of haemolytic anaemia was observed in the control group in the UK phase 1/2 study occurring 10 days after control vaccine was considered possibly related to the intervention. Three cases of transverse myelitis a disease related to the spinal cord were reported. An independent team of experts decided that one of the three could be related to the vaccine with the other two not being related to the vaccine. All trial participants have recovered, or are in a stable or improving condition.

There were four non-COVID-19 deaths reported across the studies (three in the control arm and one in the covid vaccine group that were all considered unrelated to the vaccine, with cause of death assessed as road traffic accident, blunt force trauma, homicide, and fungal pneumonia.

Pfizer Vaccine

Pain and associated swelling and redness at the site of the injection were the most common side effects. It was less among participants older than 55 years of age than among younger participants. It was also less after the second dose than the first. Less than 1% of participants across all age groups reported severe pain. Compared to pain, injection-site redness or swelling were reported by lesser percentage of participants and not increasing after the second dose. In general, local reactions were mostly mild-to-moderate in severity and not severe, resolving within 1 to 2 days.

The most commonly reported systemic side effects were fatigue and headache (59% and 52%, respectively), after the second dose, among younger vaccine recipients; being slightly lesser among older recipients. Fatigue and headache were also reported by many placebo recipients (23% and 24%, respectively), after the second dose, among younger vaccine recipients and less among older recipients. Slightly more fatigue (in 3.8%) and headache (in 2.0%) were reported after the second dose.

Fever (temperature, ≥38°C) was the third reported side effect after the second dose by 16% of younger vaccine recipients and by 11% of older recipients. More participants reported fever after the second dose than the first and it was quite low. Two participants each in the vaccine and placebo groups reported temperatures above 40.0°C. Younger vaccine recipients were more likely to use antipyretic or pain medication than older vaccine recipients more after the second dose than the first. Fever and chills were observed within the first 1 to 2 days after vaccination and resolved shortly thereafter.

Lymphadenopathy or swelling of the lymph nodes in the arm pit was the other side effect reported by 64 vaccine recipients (0.3%) and 6 placebo recipients (<0.1%). Four related serious adverse events were reported among vaccine recipients (shoulder injury related to vaccine administration, right axillary lymphadenopathy, paroxysmal ventricular arrhythmia, and right leg paraesthesia). Two vaccine recipients died (one from arteriosclerosis, one from cardiac arrest). Four placebo recipients (two from unknown causes, one from haemorrhagic stroke, and one from myocardial infarction) also died. No deaths were considered by the investigators to be related to the vaccine or placebo.  

There were four cases of Bell’s palsy—a facial paralysis that is often temporary—were observed among 18,000 volunteers over two months in the Pfizer/BioNTech trial. It is unclear whether the cases were provoked by the vaccine or whether it is similar to what occurs in the general population.

Pregnant women were not included in the vaccine trials. Therefore, they are not in the first group of those participants prioritised for the vaccine. However, there are probable pregnant volunteers who want to go through the trials and obtain the vaccine if suitable.

The Russian vaccine, Sputnik, is in the trial stages in India, and only after the results in India would it be available for use based on the results.

There are three issues besides the side effects that would contribute towards the final decision on the vaccines to be chosen. The first is that most vaccines require two doses. This makes vaccination logistics difficult as invariably some will miss the second dose. Only Johnson and Johnson vaccine, still behind in phase trials, requires one dose.

The second issue is the need for storing some of the vaccines at very low temperatures. This issue alone may force India not to skip the Pfizer vaccine. The Oxford vaccine does not require such low temperatures.

The third issue is cost. Pfizer and some vaccine manufacturers have indicated that they would like to make profits out of the vaccine, while others have indicated a willingness to keep costs low for larger populations. The Oxford vaccine is available at lower cost as well as the Johnson and Johnson vaccine when available.

What is my final message? The ones who suffered severe side effects have said that the side effects are nothing compared to severity of the COVID disease itself. It is anticipated that most people will escape “severe” side effects, defined as those that prevent daily activity. When the vaccine is made available to you, take the vaccine. Anticipate some side effects. Consider it a bonus, if you have no side effects. Be prepared to take paracetamol tablets as others have taken similar medications in other countries.                     

Writing this in simple language was not easy. It is possible that there are some who have questions relating to the side effects. Please feel free to ask them in the comment section of my blog or LinkedIn or Face Book. Experts reading this may have more current information regarding the side effects. Please feel free to add them. It would be useful if those who are reading this can share their vaccine experience, if they do get the first and second doses of the vaccine.

My blog;

Published by rajaratnamabel

Having completed my undergraduate medical education from Christian Medical College, Vellore, India. Then I had the privilege of completing my Master of Public Health from the Johns Hopkins University, Baltimore, USA. I could also complete my PhD in Chennai, India. Based on my extensive work in nutrition backed by a number of scientific publication, I also received the Fellowship of the International College of Nutrition (FICN). I retired from active service in 2005. Since then God enabled me to be a Consultant Public Health Physician, at the SUHAM Trust of the DHAN Foundation in Madurai. I am involved in providing community based health care support to a large number Self Help Groups in 14 Indian states.

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