Trump and Bobby Junior cancel vaccine development
Cornell University researchers evaluated the effects of HPAI
on a herd of 3,876 dairy cows living on a farm in Ohio that experienced an
outbreak in spring 2024 after the transfer of 42 healthy-looking lactating cows
from a Texas farm. The team analyzed animal- and herd-level data collected
before, during, and after the outbreak (March 8 to June 7).
The ongoing US HPAI outbreak began in 2022, leading to the
deaths of nearly 175 million birds. The virus spilled over into mammals and, in
March 2024, dairy cattle. So
far, 1,074 herds in 17 states have been infected.
Infected cows 6 times more likely to die
When the outbreak began on the Ohio farm, 3,433 of 3,876
cows (88.6%) were lactating. In total, 777 cows (20.0%) were diagnosed as
having flu based on severe mastitis (inflammation of breast tissue) leading to
a drop in milk production, loss of appetite, apathy, and decreased rumination
time. Sick animals were segregated to a hospital pen next to those used for
healthy non-lactating cows.
Of the 777 sick cows, 776 were lactating, and 1 was in the
dry period, with most affected cows at the mid-to-late stages of lactation and
at the second or greater lactation. Acute illness lasted, on average, 7.9 days,
and cows stayed in the hospital pen for, on average, 5.1 days.
Notably, 53 of 777 sick cows (6.8%) died or were euthanized
within, on average, 13.6 days after diagnosis, while another 245 (31.6%) were
culled within 20.6 days
after diagnosis. Relative to uninfected cows, sick cows were at a sixfold
increased risk for death (relative risk [RR], 6.0) and a more than triple the
risk of being removed from the herd (RR, 3.6).
Seroprevalence (presence of avian flu antibodies in blood)
was 89.4% in the herd, with 76.1% of seropositive cows infected. Risk
factors for infection were having 100 to 200 days into milk production (number
of days lactating since calving) and having given birth more than once.
Biosecurity measures, vaccine development
Economic losses from decreased milk production (about 900 kg [1,984 pounds] per cow) for 60 days and cow loss added up to $950 per cow, for a total of $737,500.
The authors said that while pasteurization inactivates the
flu virus, enabling safe human consumption, decreased milk production
represents an enormous financial burden to the 9.3 million–cow dairy industry.
Mastitis mitigation is complicated, the authors said,
because the condition usually is prevented through pre-milking teat cleaning
with a germicidal solution. But in this case, those practices could spread the
virus to the next cow.
"Even if they [the cows] recover, that's going to cost
a dairy farmer $367 on average in milk losses," coauthor Matthew
MacLachlan, PhD, said in a Cornell news release. "Although there
are some government support programs for dairy farmers, they aren't as generous
as they are for poultry farmers."
But consumers won't necessarily see higher milk prices.
"A lot goes into milk prices," MacLachlan said. "There's
marketing, packaging, transportation and many other factors."
First author Felipe Pena Mosca, DVM, PhD, said, containment
will necessitate a multistep process: "One key strategy is implementing
biosecurity measures to minimize these outbreaks, and the next step is
developing vaccines."
