Dr Shrey Srivastava, an internal medicine specialist at the Sharda Hospital in Greater Noida in the state of Uttar Pradesh, told Sputnik that scientists have started examining several possible theories about the link between inflammatory heart conditions after being given the mRNA COVID-19 Vaccination.
The mRNA (messenger-RNA) COVID-19 vaccines from Pfizer and partner BioNTech, and the other from Moderna have been suspected of causing myocarditis and pericarditis in some people especially young adults and adolescent males. According to researchers, there is a possibility that the mRNA, or some other component of the vaccine, might trigger inflammation in some people.
Another theory that is being considered is that the injections has been incorrectly administered sending the dose directly to the heart through veins.
According to the Centers for Disease Control and Prevention in the US, more than 870 cases of myocarditis in vaccinated people under the age of 30 have been confirmed in America out of the 86 million mRNA vaccine doses administered.
To find the causes of this vaccine-induced myocarditis (inflammation of heart muscles) and pericarditis (inflammation of the sac surrounding the heart muscle), doctors and scientists in the US are examining samples of heart tissue from people who developed myocarditis or pericarditis after being vaccinated.
In the midst of all these investigations, India’s first locally developed mRNA COVID-19 vaccine, HGCO19, is undergoing its Phase II and Phase III trials.
Last month, Sanjay Singh, chief executive of Gennova Biopharmaceuticals, based in the city of Pune, told NDTV that the company's HGCO19 is being peer-reviewed and he was optimistic that it will be in the market by the end of this year.
According to Singh, Gennova has succeeded in developing its vaccine to remain stable at temperatures of between 2 and 8 degrees Celsius.
According to experts, mRNA vaccines are generally considered safe because mRNA is non-infectious, non-integrating in nature, and can be degraded by standard mechanisms of cells.
"They are highly efficacious because of their inherent capability of being translatable into the protein structure inside the cell cytoplasm. Additionally, mRNA vaccines are fully synthetic and do not require a host for growth, for example, eggs or bacteria. Therefore, they can be quickly and inexpensively manufactured to ensure their availability and accessibility for mass vaccination on a sustainable basis," India's Department of Biotechnology said in a statement in April this year.
But the question arises: Is it possible that HGCO19 will have similar side-effects to rival mRNA vaccines produced by Pfizer Inc. and Moderna?
"With respect to HGCO19, it was approved based on safety and tolerability data from well-conducted Phase II and Phase III trials after ensuring adequate Safety, Tolerability, and Immunogenicity in healthy subjects. Though not much data is available on the possibility of myocarditis, the vaccine is supposed to be safe and efficacious according to available scientific data," renowned Hyderabad pulmonologist, Dr Viswesvaran Balasubramanian, told Sputnik.
The consultant from Yashoda Hospital said that myocarditis and pericarditis usually have symptoms such as shortness of breath, chest pain and palpitations.
"However, most of these complications are self-limiting and tend to respond well with medicine and rest and most can resume activity in a short span of time. Though it can be associated with any sort of vaccination, it is more commonly reported with mRNA-based Pfizer and Moderna vaccines," Dr Balasubramanian said.
'Benefits of Vaccine Outweigh Side-effects'
"With both the mRNA vaccines that are available in the US and other countries - namely Pfizer and Moderna - there have been some rare cases of myocarditis and pericarditis and these have been mainly seen in young men, especially after the second dose," Dr Trupti Gilada, an infectious disease specialist at Masina Hospital in Mumbai, told Sputnik.
"The side-effect definitely exists but the benefits from the vaccine far, far outweigh any side-effects. Also the side-effect is not very severe," she added.
She said that most of these patients have had a very benign course of illness and only required symptomatic treatment, and all have recovered from this complication.
Dr Gilada also said that there isn't any way to predict which individual will get the side-effect and there is no way to avoid the side-effect.
"So all we need to do is keep an eye out for this side-effect ... But we need to remind people that all the side-effects are really there," she added.
mRNA Vaccines VS Conventional Vaccines
Dr. Gilada explained that the mRNA vaccine is different from the other traditional vaccines in the way they provoke the immune system into mounting an immune response. In traditional vaccines, small inactivated particles of the virus or the disease-causing organisms are injected into the body which will essentially contain the protein that in turn will evoke an immune response.
However, in the case of an mRNA vaccine, no protein or any part of the virus is injected. Instead, a tiny piece of the mRNA is used which will eventually use the cell machinery in the human body to make the protein.
"Vaccine-induced spike protein IgG antibodies prevent attachment of SARS-COV-2 to its host cell via spike protein binding to the angiotensin-converting enzyme 2 receptors, and thereby neutralises the virus," Dr Srivastava of Sharda Hospital, told Sputnik.
So, created in a laboratory, mRNA triggers an immune response inside the recipient's body by producing antibodies, which protects it from getting infected if the real virus enters.
"There is a myth that mRNA will change the genetic make-up of the body which is untrue - because the mRNA never enters the nucleus of the cell. So, there is no way that the mRNA can ever get integrated into the genetic material of the human being or any animal where this vaccine is injected," Dr Gilada revealed.
'HGCO19 Vaccine Would be a Good Option'
Dr Srivastava said that mRNA vaccines have been studied and used for decades and the incidence of complications is on the decrease. The chances of contracting myocarditis would be much lower forin HGCO19 and it's curable too.
"HGCO19 vaccine would be a good option as mRNA is neither a live vaccine nor a part of the virus," Dr Srivastava said.
He also revealed that Gennova has used the most prominent mutant of spike protein (D614G) for this vaccine and it uses the adsorption chemistry to attach the mRNA to the nano-lipid carrier’s surface to reinforce the discharge kinetics of the mRNA within the cells compared to the encapsulation chemistry.
Dr Srivastava also noted that the indigenous mRNA vaccine can "potentially" be used with other approved vaccines.
Doctors and health experts, meanwhile, highlighted the several disadvantages of mRNA vaccines including poor immunogenicity in humans, instability concerns, induction of anti-vector immunity, and decreased translation into protein.
"Although mRNA vaccines are efficacious, there are certain drawbacks that need to be tackled which include the need for deep cryogenic storage of the vaccine which complicates its deployment, particularly in lesser developed countries where the facilities for cold chain storage are limited," Dr Balasubramanian said.
Last week, Moderna announced that the US Food and Drug Administration (FDA) needs more time to evaluate recent international analyses of the risk of myocarditis after vaccination.
The FDA has put Moderna’s Emergency Use Authorisation (EUA) request for its COVID-19 vaccine (mRNA-1273) for adolescents on hold, "as it needs more time to review and complete its assessment about the security and efficacy of the jab for those aged between 12 and 17".