The four main drug companies making COVID-19 vaccines have sold a combined $18.6 billion worth of the shots in the first half of 2021, and sales are expected to reach a combined $60 billion by the end of the year.

The big picture: Even though the U.S. represents less than 5% of the global population, the U.S. market makes up 41% of the vaccine sales.

For every premium dollar that CVS Health's insurance arm, Aetna, collected in the second quarter, it paid a little more than 84 cents to medical providers — a "medical loss ratio" that was a lot higher than Wall Street expected.

The big picture: Health insurers were the main beneficiaries of the pandemic last year, as the widespread delay of doctor visits and procedures greatly offset what they had to pay for COVID-19 hospitalizations.

Now that routine care is back, and COVID-19 hospitalizations are on the rise again, CVS executives said the pandemic is a "modest negative" for the rest of 2021.

Sales of AbbVie's blockbuster anti-inflammatory drug Humira have declined internationally, as cheaper copycats known as biosimilars gain more traction in Europe. But Humira sales continued to rise in the U.S. last quarter because Humira biosimilars are locked out of the country until 2023.

Why it matters: Cheaper versions of Humira exist, but Americans don't have access to them due entirely to AbbVie's "legal strategy" of delaying entry.

The Department of Justice has joined whistleblower complaints that allege Kaiser Permanente knowingly made its Medicare Advantage patients look sicker than they were, as a way to obtain more money from the federal government.

Why it matters: For years now the federal government has cracked down on fraudulent coding in Medicare Advantage. But going after Kaiser Permanente, a company that many view as the gold standard for Medicare Advantage, indicates the problem may touch almost every corner of the industry.

The FDA's new approval status of Semglee marks the first biosimilar insulin that is "interchangeable" with its brand-name comparison.

Why it matters: Pharmacists could substitute Semglee over Lantus without running it by a physician, just like how it works with regular generic and brand-name drugs. But even though Semglee is the cheaper option, it is still priced at almost $100 per vial.

UnitedHealth Group, HCA Healthcare and Pfizer have been the most notable health care companies to post Q2 earnings so far, but this week has been chock-full of others.

🏥 Hospitals: The second quarter for Universal Health Services was so profitable that it returned $189 million in federal coronavirus bailout funds. But executives cautioned higher COVID cases may lead to labor shortages.

Biogen recently submitted a paper to JAMA, a top medical research journal, that analyzed results from the clinical trials of its new Alzheimer's drug, Aduhelm. However, Biogen later withdrew the paper because JAMA considered rejecting it unless edits were made, according to two sources familiar with the matter.

Why it matters: The FDA's decision to approve Aduhelm has been mired in controversy; experts say there simply isn't strong enough data to show the drug works. And it appears medical journal reviewers also weren't sold on Biogen's interpretation of the data.

Latino children in the U.S. are twice as likely to be uninsured as non-Latino children, according to an analysis by the Georgetown University Center for Children and Families.

Why it matters: More than 1.8 million Latino children in the U.S. have not had health insurance since before the pandemic, putting them at greater risk for COVID-19. The virus has hit Latinos especially hard, resulting in higher infection rates, hospitalizations and unemployment.

Biogen executives used their earnings day to take aim at critics and the media, saying the federal approval of the company's new Alzheimer's drug, Aduhelm, "has been the subject of extensive misinformation and misunderstanding."

Why it matters: Biogen has billions of dollars on the line with this drug, and uptake has been very slow so far due in part to the blowback. But the company's grievances don't change the fact that Aduhelm failed to slow the progression of Alzheimer's in late-stage clinical trials.

Turquoise Health has raised $5 million in a seed funding round that will expand operations at the health care price transparency startup.

Why it matters: Federal law requires hospitals to publish all of their various prices, but many hospitals don't comply or barely comply. Turquoise brings the data together and makes it easier to digest for patients, researchers and others in health care.