However, after millions of people have received a vaccine, very rare side effects may develop that cannot be predicted by clinical trials, so researchers and regulators will be watching closely to see how the vaccine unfolds. This will be particularly important for Covid-19 vaccines based on innovative technology. Once an mRNA vaccine has been approved, which could take 12 to 18 months, it should be easy to ramp up production. Since the manufacturing process is shorter than other vaccines – Professor Bekeredjian-Ding estimates that conventional vaccines will take a few months rather than 1-2 years – it is possible that these vaccines will evolve rapidly. This is useful in the context of the coronavirus, which will likely require mass vaccination programs. As a result, big pharmaceutical companies such as Moderna, CureVac, BioNTech and GSK (which together hold nearly half of mRNA vaccine patent applications), which have spent millions of dollars developing the vaccines, have filed patents on the technology to ensure their investments are protected. The process was faster than usual, as the researchers had already built an mRNA platform for cancer and other tested vaccines – a way to bring viral mRNA into the body. This meant that this could be put into action once the genomic sequence of the virus was divided. Most work to date on using mRNA to highlight an immune response has focused on cancer, using tumor mRNA to help people`s immune systems recognize and respond to proteins produced by their specific tumors. «This technology was very good for the field of oncology because you can develop patient-specific vaccines because every tumor is different,» said Professor Bekeredjian-Ding. But when COVID-19 hit, Moderna quickly took over, developing a prototype vaccine within days of the virus` genome sequence going live. The company then partnered with the U.S.
National Institute of Allergy and Infectious Diseases (NIAID) to conduct mouse studies and initiate human trials, all within a decade. The objective of this prospective cohort study of health workers and support staff in the United Kingdom was to assess the effectiveness of vaccination roll-out in that country, including the decision to allow a delay of up to 12 weeks in the administration of the second dose of approved COVID-19 vaccines. A total of 29,378 participants participated in the study, of which 23,324 employees from 104 hospitals were included in the analysis. This cohort included 8,203 individuals (35%) with a history of SARS-CoV-2 infection (previously positive antibodies or PCR or seropositive at baseline) and 15,121 (65%) with no history of infection. The majority of the cohort were women (N = 19,692, 84%), less than 65 years of age (N = 22,955, 98%) and no underlying disease (N = 17,450, 75%). By the end of the study period, cohort immunization coverage had reached 89%, 94% (N=19,384) of vaccinated cohort members receiving Pfizer-BioNTech COVID-19 vaccine and the remainder receiving Oxford-AstraZeneca COVID-19 vaccine. Only 1,607 (8%) received both doses at the end of the study follow-up period. The vaccine efficacy against SARS-CoV-2 infection from 21 days after the first dose of Pfizer-BioNTech COVID-19 vaccine was 70% (95% CI, 53-87), increasing to 85% (95% CI, 74-96) 7 days after the second dose. There were 51 asymptomatic infections in the unvaccinated cohort compared to 10 in the vaccinated cohort, suggesting protection against asymptomatic infection. According to this CDC MMWR, one study showed that two doses of the Pfizer-BioNTech vaccine had a 93% efficacy rate against COVID-19-related hospitalizations in patients ages 12 to 18. Shortly after the outbreak of the COVID-19 pandemic, Pfizer and BioNTech began developing an mRNA vaccine against SARS-CoV-2, as did Moderna – the latter in partnership with the National Institute of Allergy and Infectious Diseases. «Now that we know that mRNA technology works, it can be introduced to treat all sorts of health conditions like the common cold and virtually any virus — even the Epstein-Barr virus, which has been linked to multiple sclerosis and chronic fatigue,» she says.