- Moderna's experimental coronavirus vaccine stimulated an immune response in older patients that looks similar to younger patients. That response, to the dose Moderna is testing in a Phase 3 trial, compares favorably to what is seen in patients who have been infected with the virus, the company stated Monday in a presentation to a federal immunization advisory committee.
- Data from the Phase 1 trial also indicated that Moderna's shot was roughly as safe in the elderly as it was in younger people, with fewer side effects like pain or fever overall in the 56-70 and 71 and older age groups. Fever, in particular, was lower, an issue that rivals Pfizer and BioNTech considered in selecting their late-stage vaccine candidate.
- Whether the vaccine can prevent cases of COVID-19 is the subject of a massive Phase 3 trial now underway. Last week, Moderna said more than 13,000 of a planned 30,000 volunteers had been enrolled, with a goal of having all participants registered by the end of September.
Older people present a double challenge for public health in the midst of the coronavirus pandemic. They are being hospitalized and dying at greater rates, but their weaker immune systems make it difficult for vaccine makers to protect them from infection.
The data Moderna released today should put some concerns regarding its vaccine to rest. The company updated the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP) on the progress of its shot, mRNA-1273, and gave the panel the first look at data on the age groups older than 55.
Checked 57 days after the second of two 100-microgram doses, patients in the 56-70 and 71 and older age groups had levels of antibodies to the coronavirus' signature "spike" protein that compared favorably to those seen in the blood of patients who have recovered from COVID-19.
In particular, in the older two age groups, "neutralizing antibodies" — those that can actually destroy a pathogen — were above the median of the recovered patients. Though it's difficult to compare treatments across trials, the Pfizer/BioNTech experimental vaccine stimulated a response in patients 65 to 85 that was one to two times what was seen in recovered patients, according to study results recently published.
The vaccine also stimulated a response from a type of immune cell called a "T-helper" that helps the body mount a broad immune response. However, it does not produce a response from a type of T cell that can clear infected cells, which an earlier Pfizer/BioNTech candidate did.
On the safety side, systemic responses, or those that result from spurring an immune attack, were overall lower after the second dose in the older age groups than in the subjects aged 18-55. Patients in the older age group reported joint pain more often, but had lower incidence of symptoms like fever, chills or nausea.
The side effect profile will be equally important as public health authorities prepare to roll out mass immunization campaigns. Vaccines with frequent moderate-to-severe side effects will not be as attractive, a factor that appears to have influenced Pfizer and BioNTech when they selected an experimental vaccine with a lower incidence of side effects.