PHealthy t1_jdiztvk wrote

Omicron isn't a single serotype (immune recognition), it's actually a ton:

So this isn't waning immunity, it's serotype emergence that escapes immunity.

ELI5: we get a great pitcher versus the first batter but they keep changing batters as we strike them out until eventually our pitcher is terrible. Then we bring in a new pitcher to match against the best batter we've seen so far and it starts all over again.


PHealthy t1_jdin3el wrote

We really don't know much about serotype specific waning immunity, it's likely we'll have robust long term immunity from the earlier variants like alpha and delta.

The whole issue of "re-infections" is that new serotypes keep emerging not that people keep getting reinfected with the same variant.

If anyone is interested in infectious disease news: r/ID_News


PHealthy t1_ja8fy3d wrote

Given the immune environment of bats, it's thought that most hemorrhagic fevers are evolved from them.

There has certainly been a lot of press around Kitum cave but there are earlier recorded outbreaks and the pinpoint origin really can't be said definitively since viral studies were pretty cutting edge 50 years ago.

Of course, just saying it likely originated from bats doesn't really give the whole current story, there are many mammals that are thought to act as reservoir species so the cat is out of the bag...

Took a little digging but Dorothy Tovar provided some great bat facts in this COVID AMA:


PHealthy t1_j8id89r wrote

A few things to clear up:

HIV has a strong tropism for CD4+ cells so provirus integration within egg and sperm cells is fairly rare but can occur preconception:

The Integrated HIV-1 Provirus in Patient Sperm Chromosome and Its Transfer into the Early Embryo by Fertilization

When it comes to perinatal HIV infection, there are many other available modes of vertical transmission: breastfeeding, placenta, etc.... Children that don't receive ART typically don't live past 2 years old:

Prevention of vertical transmission of HIV-1 in resource-limited settings

So this more traditional transmission method can obfuscate the origin of HIV. But even then, the risk for vertical transmission is between 15% and 45%.

All this means that there are indeed plenty of mechanisms to transmit HIV perinatally but that doesn't mean it is an absolute certainty .

If anyone is interested in infectious disease news: r/ID_News


PHealthy t1_j8agln0 wrote

With no context, no one can really answer this question without just referring you to a textbook.

Immune systems are not "strong" in the sense of a muscle. Good immunity is a balanced response to appropriate stimulation. Any over-response typically either results in morbidity, e.g. eczema, Crohn's, or mortality, e.g. cytokine storm.


PHealthy t1_j7ghm2e wrote

During the pandemic, yes, SARS-CoV-2 had much higher incidence:

But the normally circulating coronaviruses as we call them are definitely still around and currently making their annual peak right now:

The usual disclaimer of course that many viruses make up the "common cold".

In case anyone likes infectious disease news: r/ID_News