* Mexico marks highest daily infection rate since Jan * Copper prices rise on earnings optimism By Ambar Warrick July 22 (Reuters) - Most Latin American currencies fell on Thursday as rising COVID-19 cases in Brazil and Mexico spurred caution, while Chile"s peso tracked mild gains in copper prices. Mexico"s peso fell 0.1%. A rise in consumer prices through the first half of July did little to spur speculation over another interest rate hike by the central bank, with COVID-19 cases rising at an exponential rate in the country. "With the policy rate already at 4.25%, still significant slack in the economy, a severe credit crunch, and relatively well anchored peso, there is likely no need at this juncture to push the policy rate much higher, as long as the FOMC maintains a highly accommodative stance and dovish guidance," Goldman Sachs analysts wrote in a note. Mexico on Wednesday posted its biggest jump in COVID-19 cases since early-January. Brazil"s real shed 0.2%, as infections rose by more than 54,000 on Wednesday. More infections are likely to cause renewed lockdown measures, and further hamper growth in Latam"s largest economy. Chile"s peso led early gains, rising 0.4% as copper prices rose on optimism over a strong second-quarter earnings season. Optimism over corporate earnings also helped investors look past recent concerns over economic growth, with broader emerging markets staging a strong recovery. Safe haven such as the dollar and the Japanese yen also came off peaks hit this week, while the European Central Bank vowed to keep policy dovish for even longer to shore up economic growth. But Latin American (Latam) assets lagged their peers due to rising COVID-19 cases in major economies. Currencies of oil exporting majors Mexico and Colombia also largely ignored gains in crude prices. The Pan American Health Organization said the Americas is facing a pandemic of the unvaccinated, as it warned countries with low inoculation rates are seeing increases in COVID-19 and repeated a call for vaccine donations. Losses in Colombia"s peso were somewhat mitigated by ratings agency Fitch saying the new tax reform bill will help stabilize the country"s strained public finances. But the agency said more fiscal action was required to bring down government debt levels. Latam stocks moved little in early trade. Key Latin American stock indexes and currencies: Latest Daily % change MSCI Emerging Markets 1326.45 1.09 MSCI LatAm 2531.09 0.64 Brazil Bovespa 125577.08 -0.28 Mexico IPC 50107.53 0.14 Chile IPSA 4282.96 0.18 Argentina MerVal - - Colombia COLCAP 1253.98 0.26 Currencies Latest Daily % change Brazil real 5.2006 -0.17 Mexico peso 20.1550 -0.12 Chile peso 749.56 0.35 Colombia peso 3858.3 -0.19 Peru sol 3.946 0.00 Argentina peso 96.3900 -0.02 (interbank) (Reporting by Ambar Warrick, Editing by William Maclean) Our Standards: The Thomson Reuters Trust Principles.