research so far indicates vaccine is safe
Lot of technical terms but gist of it is that vaccine is safe.
January 14, 2021
Interim analysis of early trial shows COVID-19 vaccine Ad26.COV2.S safe and immunogenic
An interim analysis of phase 1–2a trial published in The New England Journal of Medicine shows that the coronavirus disease 2019 (COVID-19) vaccine candidate Ad26.COV2.S had an acceptable safety and reactogenicity profile and was immunogenic after a single vaccination with either the low or high dose in both younger and older adults.
In the trial conducted at 12 centres in Belgium and the United States, 805 healthy adults between the ages of 18 and 55 years (n=402) and ages 65 years or older (n=403) were randomly assigned to receive the Ad26.COV2.S vaccine at a dose of either 5×1010 viral particles (low dose) or 1×1011 viral particles (high dose) per mililitre or placebo, administered intramuscularly, in a single-dose or two-dose schedule 56 days apart. The primary end points were the safety and reactogenicity of each dose schedule.
After the administration of the first vaccine dose in participants in both cohorts and after the second dose among participants between the ages of 18 and 55 years, the most frequent solicited adverse events were fatigue, headache, myalgia, and injection-site pain. The most frequent systemic adverse event was fever. Systemic adverse events were less common in participants 65 years of age or older and in those who received the low vaccine dose.
The researchers reported that the local and systemic reactions occurred on the day of immunisation or the next day and generally resolved within 24 hours. Further, the systemic reactions were very responsive to antipyretic drugs, and no need for the prophylactic use of such drugs was identified. In addition, after the second dose in the 18-to-55 age group, the incidence of grade 3 solicited systemic adverse events was much lower than that after the first immunisation in both the low-dose and high-dose groups, a finding that the researchers said contrasts with observations with respect to messenger RNA-based vaccines, for which the second dose has been associated with increased reactogenicity.
Neutralising-antibody titres against wild-type virus were detected in 90% or more of all participants on day 29 after the first vaccine dose (geometric mean titre [GMT], 224 to 354) and reached 100% by day 57 with a further increase in titres (GMT, 288 to 488), regardless of vaccine dose or age group. The researchers found that titres remained stable until at least day 71. Further, a second dose provided an increase in the titre by a factor of 2.6 to 2.9 (GMT, 827 to 1266).
On the other hand, spike-binding antibody responses were noted to be similar to neutralising-antibody responses. On day 14, CD4+ T-cell responses were detected in 76% to 83% of the participants in the 18-to-55 age group and in 60% to 67% of those 65 years of age or older, with a clear skewing toward type 1 helper T cells. Meanwhile, among participants in the 18-to-55 age group, CD8+ T-cell responses were detected in 51% of those in the low-dose group and in 64% in the high-dose group. Among those 65 years of age or older, CD8+ T-cell responses were lower, with an incidence of 36% in the low-dose group and 24% in the high-dose group.
“Although all ongoing phase 3 studies of other COVID-19 vaccines have assessed two-dose schedules, a single dose of Ad26.COV2.S elicited a strong humoral response in a majority of vaccine recipients, with the presence of S-binding and neutralising antibodies in more than 90% of the participants, regardless of either age group or vaccine dose,” wrote Jerald Sadoff, MD, Janssen Vaccines and Prevention, Leiden, the Netherlands, and colleagues. “In addition, during 71 days of follow-up after the first dose, antibody titres further increased and stabilised, which suggests durability of the Ad26.COV2.S-elicited immune response.”
“Whether a second dose will provide additional benefit for either improved efficacy or durability in humans, especially in elderly persons in whom the immune response after the first dose tended to be modestly lower than that in younger participants, is currently being studied in a phase 3 clinical trial,” the authors added.
Reference: https://www.nejm.org/doi/full/10.105...=featured_home
SOURCE: The New England Journal of Medicine
Re: research so far indicates vaccine is safe
Thanks for the info and link, makes good bedtime reading. Am I being presumptuous in thinking 2021 may just be a tad better than that other year?
Re: research so far indicates vaccine is safe
Has anyone gotten the second dose? Side affects? What was the outcome?
Re: research so far indicates vaccine is safe
My wife and I have the second dose scheduled for January 28th.