Giv­ing Sanofi’s flu vac­cine to­geth­er with a boost­er shot of Mod­er­na’s Covid-19 vac­cine to the el­der­ly ap­pears to be just as safe as ad­min­is­ter­ing the two apart, the two com­pa­nies re­port­ed, join­ing a small cho­rus of drug­mak­ers bring­ing good news about co-ad­min­is­tra­tion of sea­son­al shots.

The study en­rolled around 300 adults who were 65 or old­er.

All of the par­tic­i­pants had re­ceived two dos­es of the Mod­er­na mR­NA vac­cine at least five months pri­or. Then in one vis­it, they were giv­en Flu­zone, Sanofi’s high-dose quadri­va­lent flu vac­cine, and Mod­er­na’s mR­NA-1273, in­tend­ed as a boost­er. The high-dose for­mu­la­tion was specif­i­cal­ly de­vel­oped to of­fer high­er pro­tec­tion to the el­der­ly, who are at high risk for com­pli­ca­tions due to both in­fluen­za and Covid-19.

“This sea­son, more than ever, it is crit­i­cal to help pro­tect the old­er adults, who are at es­pe­cial­ly high risk for both se­vere COVID-19 and com­pli­ca­tions from in­fluen­za, which can in­clude heart at­tacks and strokes,” said Michael Green­berg, North Amer­i­ca med­ical head for vac­cines at Sanofi.

As flu sea­son ap­proach­es, ques­tions have height­ened about whether it’s safe for peo­ple to re­ceive two vac­cines at the same time. Pub­lic health of­fi­cials such as NI­AID chief An­tho­ny Fau­ci have said it’s “per­fect­ly fine” — es­pe­cial­ly if it means one can be vac­ci­nat­ed in an ex­pe­di­tious man­ner.

In a re­cent study, British sci­en­tists led by the Uni­ver­si­ty of Bris­tol looked in­to co-ad­min­is­tra­tion with three flu vac­cines and Covid-19 shots from Pfiz­er/BioN­Tech and As­traZeneca. They con­clud­ed it’s safe to get both si­mul­ta­ne­ous­ly and it doesn’t neg­a­tive­ly af­fect the im­mune re­sponse spurred by ei­ther.

Get­ting more than one vac­cine at once is shap­ing up to be a big pri­or­i­ty for vac­cine mak­ers. Mod­er­na it­self is work­ing on a sin­gle jab that com­bines its Covid-19 boost­er with an ex­per­i­men­tal flu shot; No­vavax has al­so launched stud­ies with its in-house can­di­dates.

It’s not lim­it­ed to Covid-19, ei­ther. Days ago, Pfiz­er tout­ed re­sults from a study look­ing in­to the co-ad­min­is­tra­tion of Pre­vnar 20 (its new­ly ap­proved pneu­mo­coc­cal vac­cine) and a flu jab.

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