It’s hard to imagine more depressing news than some recent studies showing that antibodies to COVID-19 fade within a few weeks — a blow to any hopes for a vaccine, or for any chance of getting out of the pandemic without years of hardship.

Don’t let it raise your blood pressure. Pendulum swinging is all part of a common pattern in health reporting, where all the attention goes to extremes — total gloom or total sunshine — when reality is somewhere in between. It can seem jarring, when this news about fast-fading antibodies comes out within a few days of the hopeful news that several human vaccine studies are showing promising results. Some vaccine makers are already moving into massive-scale efficacy trials that could yield early results before the end of this year.

One reason for the seemingly discordant news is that vaccines can induce a stronger immune response than natural infections — and for that reason several vaccine researchers I spoke to said they were unfazed.